...ish. Under normal circumstances, it operates as a suffix; it adds meaning to words, but is not meaningful in itself. Almost a word, but not quite -- something slightly askew to the rest of the language...

The most exhaustively comprehensive dictionary of the English language in history is nearing completion, but the fawning delegates who have assembled to observe the launch of the Lexicon are proving an irritating distraction to its compiler, the Doctor’s old friend Professor Osefa. Conference symposiarch Robert Cawdrey has lined up new investors who have promised to help fund the Lexicon if they are mentioned in its preamble, and Osefa thus locks herself away in her office to work. She has too much work to do by herself, but her hologlyphic amanuensis, Book, appears to be stuck on a single word which is giving him trouble. Osefa thus sets to work herself, double-checking the final entries before the Lexicon’s unveiling...

The TARDIS materialises on campus, and the Doctor emerges, enthusing to Peri about the great undertaking underway. Peri understands why someone with the Doctor’s love of words would take such an interest in the Lexicon, but remains irritated by the Doctor’s contempt for her New Englandisms, which he regards as a corruption of the language he loves. English is a living language in the truest sense of the words, expanding and evolving while never losing its grace, integrity and poetry. Cawdrey happens by and greets the Doctor, recognizing him from Osefa’s description, and as the two set off to look up Osefa and determine whether she’s finished her keynote address to the delegates, Peri wanders off on her own, fed up by the Doctor’s heaping scorn on Noah Webster and his “reforms”.

Peri visits the refectory to order lunch and a pint, and meets an enthusiastic logophile named Warren. Amused by his charming impishness and approachability, she shares lunch with him, and they challenge each other to come up with words beginning with “peri-”. Peri wins the contest due to her knowledge of botany. Warren concedes gracefully, and Peri is later surprised to learn that their conversation paid for lunch; here in the Articulate Worlds, information is a commodity, and even words have value. Warren loves language, which he feels is more vital and alive than the scholars who study it and try to pin words down to “official” definitions. As far as Warren’s concerned, words are meant to be in use, alive and evolving and being spoken -- or speaking through people themselves. Perhaps words speak people into existence, rather than the other way around...

The Doctor has brought a gift for Osefa, an original text collection of obscure, original and preposterous words -- a Time Lord gift, as it were. Cawdrey confesses that Osefa is always labouring over revisions, attempting to perfect her work, but as Symposiarch and a patron of the Lexicon, it’s his duty to see that her perfectionism doesn’t delay publication. A great deal is riding on the work being completed in time. But when he and the Doctor enter Osefa’s office, they find that she has finished her work forever, having apparently committed suicide.

Elsewhere, Book remains stuck on the same words, going back over the same memories, unable to cope with what he’s seen. Even the word “English” is no longer a comfort. Born of Anglo-Saxon roots, it is derived from Angle-ish -- like, but unlike, the language of the Angles, a definition less definite. The ish makes meaning less meaningful, and it’s in the name of the language itself. Has language never been anything but a game?

As Cawdrey tries to reschedule the conference around Osefa’s death, the Doctor studies the context of the crime scene and determines that Osefa died within a room locked from the inside. The apparent suicide note, however, is riddled with errors and atrocious penmanship. Even in the throes of despair, could the perfectionist Osefa ever have lost her grip on the language to such an extent? And if she didn’t write the note, who did? The Doctor questions Cawdrey and learns that Book may have been the last to see Osefa alive. A hologlyph can materialise and dematerialise at will; could this explain how Osefa was possibly murdered inside a locked room? The Doctor activates a search engine to trawl the faculty computers for some sign of Book, wishing to learn his version of events. Cawdrey finds the possibility of foul play disturbing, but the Doctor realises that he’s more concerned that a police investigation may bring up the question of the dubious investments he’s made to fund the Lexicon. He thus convinces Cawdrey to let him investigate personally -- for if Osefa was indeed murdered, the killer may still be somewhere on campus.

The Doctor’s search finds no sign of Book, but uncovers evidence of widespread systems failure within the faculty ordinateurs, apparently the result of internal corruption. However, as this means the security systems are down, the Doctor is able to access Book’s workspace and find out what he’s been up to recently. There, he discovers and corrects Warren’s tampering, and, much to Cawdrey’s horror, identifies the culprit through a wordplay “signature”. To those who don’t know Warren, he seems like a gauche young post-structuralist, but Cawdrey knows that Warren is in truth devoted to disrupting all linguistic endeavours wherever he may find them. Warren has sabotaged others’ work before, spreading chaos through the verbal economy of the Articulate Worlds -- and with the security systems scotched, the symposium’s safety seems sunk.

Book collects himself after a moment, although his behaviour remains unnerving, even to Book himself. Warren tries to break Book out of conventional thinking patterns by challenging him to supply definitions for obscure words and colloquialisms, but he is interrupted by a public address from Cawdrey demanding that anyone without a valid invitation report in to the faculty. Warren leaves to investigate, leaving Peri feeling left out -- but she’s coming to suspect that Warren has issues, and that his love of language isn’t as innocent as it seems. She asks Book to describe his work, and learns that he’s compiled an exhaustive list of words, including but not limited to archaisms, idiomatic spellings, acronyms, compounds, back-formations, toponyms, doublespeak, argot, scientific terms, jargon, and foreign borrowings... in other words, “exhaustive” can be taken as a literal definition. Peri wonders if an artificial intelligence such as Book can ever fully understand the depth of the language he studies. Perhaps Book really is under too much stress; perhaps this is why he now has no memory of having threatened Peri earlier. Book admits that his memories of recent events have grown indefinite...

The delegates are growing impatient, but the Doctor entertains them with a selection of amusing anecdotes, pacifying them for the nonce whilst Cawdrey scours the campus for sign of Warren. Cawdrey is facing writs from his sponsors, as he’d charged them for including their brand names in the Lexicon, and that data was the first to be lost in the systems failures. The Doctor remains concerned by Book’s absence; as his function was to collect and arrange linguistic data from all possible sources, what obscure sources and words might he have encountered? And what might they have done to him? The Doctor reluctantly turns to the only evidence available -- Osefa’s body. The brains of her species possess a resilient hippocampus which retains memories for some time after death, and the Doctor modifies the dictionary construction software used to create Book, using it to scan Osefa’s brain and create a hologlyphic reconstruction of the dead woman. Perhaps they can learn the truth from Osefa herself...

Peri and Book both understand that Book’s task to collect and define all words everywhere will, by definition, never be complete, and that despite his efforts there will always be others who seek to prevent people from communicating with each other. Still, Book never felt as though he were meant for anything else... until his expedition to Xenocubis. Osefa had received special dispensation to transport Book’s remote projectors to said world, whose inhabitants believed that in the beginning was, literally, the Word -- that in the first hundreds of millennia after the Big Bang, when space was dense enough to transmit sound, the echoes of the Big Bang gave birth to language itself. The natives of Xenocubis held that all languages were fragments or corruptions of the first great Word, which they had pledged to keep alive. Xenocubis was thus a treasure trove of archaic and forgotten words, and Book sought out and collected them all -- until he encountered an inexplicability which collected him instead...

Book feels strangely relieved to have explained himself, and Peri understands; she often tried to impress her stepfather by looking up specialist words related to his profession, but just knowing the words didn’t help them to talk. It occurs to her then that if Book is constantly seeking out new words and civilisations, he shouldn’t have time to interact with users of the dictionary. Book reveals that Osefa had created a Lexisphere, an interface between the worlds of reality and meaning; its opening was to have been the culmination of the conference, and of Osefa’s life’s work. Peri, noting nervously Book’s use of the past tense, suggests that the inexplicability which Book encountered may have been entered into the Lexicon -- which could cause trouble, unless they investigate the possibility.

The Doctor learns of Xenocubis from the hologlyphic Osefa, and sadly switches his old friend off when he realises that the copy is unaware the real Osefa is dead. Asking her about her own death would prove too traumatic, and the Doctor now has enough food for thought. Osefa’s field notes from the Xenocubis expedition contain numerous references to L.T., which the Doctor now concludes is an abbreviation for Lexical Transcendence -- a pursuit which Cawdrey regards as lexicographical superstition, but one which the Doctor feels would naturally have attracted Osefa, who had devoted her life to understanding the origins of language. She always pursued her interest in an idiosyncratic manner, as well, and the Doctor thus deduces the existence of a dedicated access portal to the Lexicon. The Lexisphere could be defined as Book’s memory, and it is thus the most likely place to which he would have retreated had he observed -- or been involved in -- Osefa’s death.

Book shows Peri to the Lexisphere, a metaphorical particle accelerator for meaning. This is where words are broken apart into quantum morphemes of significance -- but there’s something wrong, a presence within the Lexisphere which Book cannot define. The meanings of the words in the Lexicon are altering as he speaks, and Peri finds herself trapped inside the Lexisphere as an ominous rumbling begins to build to near-deafening proportions. The rumbling dies away -- but Book begins to repeat the same word, over and over, as if possessed. Ish...

Warren releases Peri from the Lexisphere, and outside, they find Book mindlessly repeating the word “...ish”. Warren and Peri flee while they still can, but Warren feels charged by his brief exposure to the Lexisphere, a world of words which felt like home to him. Peri tries to warn Warren that she sensed a living presence within the Lexisphere, and insists upon finding the Doctor -- but when Warren learns that the Doctor is with Cawdrey he takes his leave, intending to take his chances elsewhere.

Only the Doctor and Cawdrey are unaffected by whatever has caused the other delegates to stick on the word “...ish”. Cawdrey identifies the original speaker as Book... who can project himself to any point on the campus. How has Book done this to the delegates? An infectious agent, or some technological virus also responsible for the corruption in the faculty ordinateurs? The Doctor ushers the affected delegates into the conference chamber to wait; they are physically unaffected, but if their mental breakdown continues for much longer neural atrophy may set in. Sure that Warren is responsible for this fiasco, Cawdrey searches the campus for help but finds no one else immune; also, the communications have been jammed, leaving him with no way to call off-campus for help. In the campus library, he finds that things are worse than they thought -- the text in the books is shifting around, and Osefa’s suicide note seems to be rewriting itself as he watches...

The happily unaffected Peri is reunited with the Doctor, who suspects that his natural talent for resisting brainwashing has rubbed off on her. He theorizes that the delegates have become stuck on a single word because they’re trying to puzzle out its meaning. Sometimes one finds oneself wondering why a certain word seems to fit a certain thing or concept, and one repeats the word to oneself, over and over again, trying to puzzle the meaning out -- but the more one repeats the word, the less meaningful it becomes. The delegates have somehow lost the mental connection between sound and significance, and their minds are unable to cope.

Book keeps coming back to the same things: the events of Osefa’s death, his attempt to correct the mistakes in her keynote speech, and the word “...ish”. Osefa intended to address the problem of “word killers,” the lexicographers of the past who were forced to remove archaic words from dictionary updates due to limited space in the recording media. But words cannot ever really be killed. Warren tries to enlist Book’s help to get into the Lexisphere, but Book has other things on and in his mind. For a moment Book feels hope when Osefa herself materializes before him, but it’s just the hologlyph which the Doctor had created, an echo of Osefa with a life of its own. The hologlyph, apparently under the impression that she is the real Osefa, continues to work on her keynote address, on the topic of lexical transcendentalism. A transcendental number, such as pi, can never be defined as a finite or repeating series of digits -- so what would a transcendental word be?

As Peri describes to the Doctor her encounters with Book, Warren and the Lexisphere, the sound of birdsong stops momentarily and then restarts. The effect is spreading through all forms of language on campus, but only some forms of communication suit its purpose -- for example, body language and the language of architecture remain unaffected. Everything seems to tie into the concept of lexical transcendentalism, the search for the mythical longest word in the cosmos. A short word such as “so” can have dozens of different meanings, but longer words usually only have one or two. The theoretical longest word, the Omniverbum, would of its nature be so dense in meaning that reality itself would warp in its presence. The Doctor doubts whether Book and Osefa found the Omniverbum itself, but perhaps they found a fragment of it... a sentient word which devours meaning, an “...ish”. Cawdrey arrives, breathless, to report that the entire campus has been affected, and the Doctor takes charge and orders him to shut down the Lexisphere, now just another way for the ...ish to spread. To protect Cawdrey and Peri from further exposure to the ...ish, he fits them with transgalactic babel masters, which will censor out the offending syllable if it’s spoken in their vicinity. In the meantime, the Doctor has another booking...

Cawdrey resists the Doctor’s theory; he’s made his fortune dealing in words, and can’t accept the possibility of an intelligent and deadly one. As Peri tries to shut down the Lexisphere solo, however, the words on the computer monitors shift about, trying to trick her and Cawdrey into reading the word “...ish”. The panic-stricken Cawdrey begins to babble, wishing he could polish up his past, extinguish his mistakes and relinquish all responsibility. Peri sneezes, atishoo, into a tissue. The ...ish is still getting to them both...

Osefa’s hologlyph materializes, distracting Warren while the Doctor and Book flee. Warren lets them go; there’s nowhere outside language where they can escape. Warren himself remains to define his objectives to Osefa, who listens patiently -- and then tells Warren what he’s really all about.

Book retreats to his office, where he shows the Doctor the controls for his remote projectors -- which the Doctor reluctantly smashes, confining Book to the campus. Warren can spread the ...ish without Book’s help, but it’s presumably the significance of using Osefa’s assistant to destroy language which gives the act meaning. Book reveals that he has an in-built ability to disassociate himself from the language in the Lexisphere, and he’s been maintaining his sanity by accessing different definitions of “ish”, thus repeating the same sound but not the same word. He and the Doctor compare notes, and conclude that Warren and the ...ish have different agendas; Warren wishes to destroy language everywhere, but the Ish has remained on campus even though it could easily have influenced one of the delegates to wander off the grounds. Whatever it’s after must be here on campus -- and the most likely target is the Lexicon. Book blames himself for bringing the ...ish to the Articulate worlds, but the Doctor absolves him; it’s Book’s nature to compile language, and the ...ish merely took advantage of this.

Peri removes her babel master, as she and Cawdrey are already under the ...ish’s influence; soon, they may be unable to communicate at all. Acknowledging the truth of this, Cawdrey realizes he must confess the truth about Warren. Though Warren doesn’t realize it himself, he is also a hologlyph, programmed by Cawdrey, fitted with all the latest improvements, and connected to the Lexisphere, as is Book. Cawdrey designed him as a logophile so he would be attracted to word fests and language conferences, and as a mischief-maker so he would sabotage the work of the Lexicon’s competitors -- but he learned too late that he’d underestimated Warren’s potential for wreaking havoc. Ever since then, he’s tried to keep Warren out of serious trouble while contributing anonymously to the Lexicon -- but if Warren ever learns the truth about himself, he’ll realize that he can spread the ...ish directly without having to go through Book.

Book and the Doctor define their enemy, the ...ish, as a fragment from within the Omniverbum, a syllable which feeds by breaking down language and consuming fragments of meaning. When Book inadvertently entered it into the Lexicon, he introduced it to a whole new feeding ground -- but, sensing his knowledge of the upcoming conference, it remained dormant until the linguists and logophiles arrived. They were the main course, but the Lexisphere is its new home, and that’s where the Doctor must strike back against it.

Cawdrey shuts down the Lexisphere, but then Warren materialises, having learned the truth about himself from Osefa. Peri tries to talk sense to him, but he’s beyond reason, and Peri finds herself succumbing to the ...ish. Cawdrey also fails to get through to him, and Warren reveals that Osefa knew the truth all along -- and said nothing, because she pitied Cawdrey and knew he would never be capable of producing anything worthwhile on his own. This revelation pushes Cawdrey over the edge, but just as Peri is about to follow, the Doctor arrives and pulls her back into coherence. He then bluffs Warren into a seizure by pretending to destabilise the hologlyph projectors, giving Peri a chance to update him -- but Warren then flies into a real panic when he senses the ...ish deserting him. It seems his ambition to destroy all language isn’t to the ...ish’s taste after all...

The Doctor offers himself up as a new host for the ...ish, and tries to communicate with it within the space of his vocabulary. Lost, isolated, confused, hungry -- none of these words convey the exact sense of what it feels, but that’s the nature of the English language. There’s more to meaning than just bland description -- and English is a living language, the most powerful in the Universe, one which even the ...ish cannot control or comprehend. The Doctor realizes that the ...ish wants to return to its natural habitat, the Omniverbum, and offers to help it do so if it releases the delegates. However, the ...ish expels the Doctor from the realm of meaning back into the real world, where he finds Cawdrey mad, Warren begging the ...ish to return to him, and Peri stuck repeating “...ish”. Has meaningless susurration won out after all?

The hologlyphic Osefa addresses the assembled delegates at last, finally appreciating what’s been happening here. Instead of her prepared speech, she tells a story about her friend the Doctor, a man with a unique manner of speech. Sometimes his wit and language is his only line of defence against the evils he faces. But what if some day the Doctor were to meet an enemy from within the realm of language? What if one day he is literally unable to talk himself out of danger? Without language, all is lost. Her message delivered, Osefa vanishes again, much to the watching Book’s despair.

All seems lost until Peri speaks one of her American colloquialisms -- and the Doctor realises that this may be the weapon he needs. The ...ish consumes meaning, one word at a time -- but if he and Peri give it conflicting English and American words with the same definition, it won’t know which to consume first. Lift and elevator; tap and faucet; porridge and oatmeal; biscuits and crackers... The ...ish finally gives up and retreats to familiar surroundings, and the Doctor and Peri flee from the Lexisphere, taking Cawdrey with them, as they hear the rumbling approach of the Omniverbum. Warren remains behind, welcoming the approach of the transcendental word -- and the Doctor realizes that though the ...ish has chosen him as a host through which to return home, Warren intends instead to bring the Omniverbum out of the realm of meaning and into the real world, disarticulating meaning completely and threatening the structure of reality itself. The only way to stop him is to drive the Omniverbum back by hitting it with the full force of the English language, the only thing more powerful than the longest word itself. Though it means destroying his life’s work, Book disassociates himself from the word horde within the Lexicon, overloading the Lexisphere with meaning and driving the Omniverbum back into pure conceptual space.