Returning to the present day, a still-unsettled Sarah closes the Fissure with the converter, insisting to her young friends that they cannot venture through any more for fear of changing something and thereby altering the present. She ushers them all home, but they begin to notice their friend is behaving oddly.

Once they return to Bannerman Road Clyde and Rani tell Luke to try and find out what has happened. Meanwhile, Sarah goes up to her attic, where Mr Smith confirms that the Time Fissure has been closed. Sarah then asks him to give details of the local area over the past century – specifically a village named Foxgrove. He tells her that the village – known for the remains of a Cistercian Abbey – was demolished in 1964. Sarah again seems to recognise the area. Closing the attic door she goes over to her desk and removes the photo of her parents. She looks at it but assures herself she must not be tempted by what she has uncovered.

Soon Luke arrives, and voices his concerns that his mother is not okay. She shows him the photograph and tells him it is of her parents – Barbara and Eddie Smith, who were killed in a road accident in August 1951 when she was a baby, living with them in Foxgrove. She reveals that she was not in the vehicle at the time – before they got in the car her parents abandoned her at the side of the road – not having told anyone about where they were going.

Luke begins to realise that his mother secretly wants to return to Foxgrove and urges her to do so, to meet her parents before they die. However, Sarah is reluctant – realising this may be a trap, one she must not fall into.

However, that night Sarah dresses herself up in an old period dress and puts on her make-up, preparing to venture through the Fissure – unable to resist the temptation laid down before her. Just as she is about to leave Luke finds her and tells his mother he wants to go with her. Promising herself and her son that they will only be gone a short while, Sarah leaves.

Arriving at the abandoned shop again, Sarah reopens the Fissure and, after a quick crisis of conscience and some encouragement from Luke, steps through the portal, leaving her son on the other side with the Energy Converter. However, as soon as Sarah has stepped through the portal it begins to close, and Luke dives through just in time. As the Trickster appears in the shop, revelling in the fact his plan in fruition, both Sarah and Luke find themselves on the hillside overlooking Foxgrove.

Sarah insists the Fissure is still active, even though closed, and tells Luke it will eventually open again. They then make their way toward the village, unaware they are being watched by Oscar.

Back in 2008, Clyde goes to Sarah’s house to call on Luke, but finds he is gone. He goes across the road to see Rani, and together they open up Sarah’s house with the spare key. Up in the attic Clyde worries that Sarah and Luke may have been abducted. Mr Smith has no information either, but insists there are no signs of alien activity. However, he theorises that Sarah has gone back into the past, now aware that it will take her to see the parents she never knew.

He then detects an energy spike coming from the attic, which Clyde and Rani discover is emanating from a small metal cube – which Clyde has encountered before. He explains that his old friend Maria was given it as a gift from Sarah, and that soon after the group came under threat from a being known as the Trickster and his assistant, known as the Graske – who took Sarah out of time and tried to alter history. Maria was kept safe from these changes by the box, and used it to save the day when he, like the rest of the world, forgot Sarah had ever existed. Now that the box is active they realise something else is going to happen, and hurry to the abandoned shop, hoping the box might help them open up the Fissure so that they can warn Sarah and Luke.

Meanwhile, in 1951, Sarah and Luke discover the entire village is gathering for the annual fete, and they agree to make a short visit so that Sarah can at last see her parents. However, on the way Sarah begins to fear what kind of people her parents might have been – especially since they apparently abandoned her when she was young. Despite this, Luke presses on and they soon find themselves at the fete – where they overhear a young woman talking to a baby – a child named Sarah Jane.

Watching the young mother tend to her child, Luke claims that she appears to be a good parent, but Sarah wishes to know why she was abandoned. Despite Luke’s warnings that this was not their original plan, Sarah approaches Barbara, introducing herself as Victoria Beckham, and Luke as her son David.

Soon they are joined by Barbara’s husband Eddie – whom has just arrived, having parked his car in the village square. Both parents dote over their young child, much to Sarah’s joy. She then walks off with Barbara to help man the refreshment tent, and Luke is left to wander around – finding that Oscar is nearby. He then picks up a discarded newspaper and begins reading it.

In the refreshment tent Barbara and Sarah, alias Victoria, begin talking about motherhood – at which point Barbara reveals she and Eddie intend to have more children, so that Sarah Jane will not grow up alone. She recalls the first time she met Eddie, in a canteen where she was working, and reveals they used to send each other notes (in which they always referred to each other as ‘Mr’ and ‘Mrs Smith’), a habit they have not shaken off, as Barbara reveals when she shows Sarah a note written to her: “Mrs Smith, chips for tea please xxx”.

In the present day, Rani and Clyde arrive at the abandoned shop, where they attempt to use the box to reopen the Fissure, but to no avail. However, the box does react to something, another warning…

In Foxgrove, Eddie and Barbara again dote upon their daughter, and Sarah realises her parents really did care about her. Barbara ponders what a world her daughter will grow up in, and Sarah assures her that she will lead a good life. She then decides it is time to leave, and she bids a fond farewell to her parents before returning to the village square. Luke soon joins her, saying it is time to go. Sarah agrees, safe in the knowledge that although she is no closer to understanding why her parents abandoned her, at least she knows they were good people.

Luke shows her the newspaper he has found – a souvenir to show Clyde and Rani. Sarah glances at it and is shocked by the date – August 18th. Realising Oscar was lying to her when she first crossed the Fissure; she reveals that this is the day her parents were killed, the day she was left behind. Glancing around the square Sarah sees a nearby car, which she remembers is Eddie’s, and realises that she could save her parents by putting it out of action with her Sonic Lipstick.

Luke stresses that they cannot change the past but Sarah’s mind is made up. Claiming that she deserves some reward for leading an otherwise selfless life, in return for all the lives she has saved without a second thought, she vows to alter time. Luke warns that in doing so she may change the world in catastrophic ways – she might never meet the Doctor or Rani and Clyde, she may well never meet him, her own son. However, Sarah insists she only wishes to look through the Fissure and see how her life might have been, before restoring the car and fixing the change if anything wrong has occurred.

Convincing herself that this is not a trap, rather a reward, Sarah ignores Luke and zaps the car with the Sonic Lipstick – now her parents cannot leave. She and Luke then hurry back to the site of the Fissure, unaware that the nearby remains of the Abbey have started to crumble.

Back at the fete, the sound of thunder is heard, but as Eddie notices, there are no clouds. Nearby, Oscar is marvelling at the sudden change in weather: “It’s happening…time for me to collect my prize!”

In the present day, Clyde and Rani watch as the box continues to flash. Suddenly the Fissure opens again and Oscar steps out. He regards them both then morphs into his true form – he is the Graske, the Trickster’s assistant. Clyde and Rani run away but the Graske is hot on their heels. Eventually the pair hides behind some rubbish bins; just as everything starts to shake…time is changing…

Sarah and Luke arrive at the Fissure and try to look through it, but to no avail. Instead they step through and emerge on a barren landscape – the ruins of a destroyed London.

Soon Rani and Clyde find themselves on a similar landscape – next to a devastated Tube station.

The Trickster explains that although Sarah saving her parents was only a small change in the grand scheme of the universe, the village stands on a fault line of the web of time – the remotest of changes, if occurring there, is enough to break open time itself and allow him to walk upon the real world forever, instead of the temporary existence he currently lives in the shadow dimensions. Despite his claims that he cannot be stopped now that Sarah has given him the Earth, Sarah and Luke hurry back through the Fissure.

Meanwhile, elsewhere in the desolate remains of London, Clyde and Rani explore the alternative timeline they have been thrown into – protected from change themselves by the box.

In 1951, Luke insists that Sarah must allow her parents to drive away and face their own deaths in order to restore balance, but Sarah insists – if only to herself – that there must be another way. Above their heads great banks of cloud begin forming – the Trickster is beginning to enter through from the shadow lands.

Soon the fete is called off and everyone hurries to the village hall. Barbara and Eddie are bemused by the sudden change in weather but carry on nonetheless.

Back in the alternate present day, Clyde admits that he feels out of his depth, and Rani agrees. However, determined to find a way home, they chase after the Graske, whom they find stalking the nearby area.

Meanwhile, Sarah explains to Luke that although the Trickster exists fully in the alternate future, in 1951 he is yet to manifest himself in corporeal form, so there is still time to stop him. Sarah laments there may only be one man who can help, but he is never around when she needs him – or is he?

Standing nearby is a large blue Police Box, and immediately Sarah runs up to it, calling out the Doctor’s name. However, the only occupant is a Policeman – the box is not a TARDIS. Sarah, somewhat disheartened, resolves herself and insists she and Luke must deal with the Trickster themselves.

Rani and Clyde discover the remaining humans, all working as slaves to the Graske. Amongst them is Rani’s mother Gita, whom Rani calls out to, unwittingly revealing herself and Clyde to the Graske. However, the creature does not attack them; instead he labels them deviants and ignores them.

Whilst Sarah and Luke hurry to the village hall in 1951, Rani and Clyde approach Gita, who appears not to recognise them. She explains that the remaining humans are used as miners to gut the Earth of minerals, and tells them that the person who handed the world to the Trickster is Sarah Jane Smith. She recalls the legend that by stopping her parents from getting in their car the Trickster was able to enter the world, through something called the Abbot’s Gateway. Clyde realises that they must go to 1951 and warn Sarah and Luke what is about to happen, and the only way back in time is to confront the Graske.

In the village hall in 1951, after Eddie laments that he wished to take his wife and child for a drive that afternoon, Sarah and Luke (still under the alias’ of Victoria and David Beckham) arrive and ask he and Barbara if they have noticed anything sinister in the village recently. They claim they have not, but Barbara agrees to go with them and see if she can find anything that may have changed. Eddie remains sceptical of the two strangers, and stays behind with baby Sarah.

In the alternate future, Clyde and Rani gain audience with the Graske, who explains the minerals his slaves mine will be used to give the Trickster the power to leave Earth and take over other worlds. Clyde realises that the Graske is simply the Trickster’s slave, but the miniature creature denies this fiercely, eventually revealing that his work for the Trickster is payback for the Trickster having saved his life when his spaceship almost crashed. The Graske tries to take the box from Rani and Clyde so that he will be free from the Trickster’s power, but they tell him that he can only have it if he opens the Fissure to let them return to 1951. Ultimately he agrees, and opens the portal for them, but only on the agreement that Clyde stays behind with the box.

Rani hurries through the portal, vowing to save her estranged mother, and upon arriving in 1951, hurries to the village, where Sarah, Luke and Barbara have made their way to the ruins of the Cistercian Abbey. Barbara asks about Sarah’s watch, which she is using to scan for the Trickster, but Sarah insists she cannot say any more about herself, for fear of making the time alteration worse.

Back in the village hall, Rani arrives and asks the crowd if they have seen Sarah Jane Smith. Eddie, very suspicious, indicates his baby girl, but Rani insists the woman she is looking for is older – Eddie realises she wants Victoria Beckham.

As the rain begins outside, Rani hurries to the main square, where Luke greets her and takes her to the Abbey, where again she mistakenly calls Sarah by her real name, thus arousing Barbara’s suspicions. Rani then warns Sarah about what has happened now that she has stopped Eddie and Barbara leaving, and that they must now look to the Abbot’s Gateway, an archway close to where they are standing. Sarah realises this must be the place of the Trickster’s arrival, for hallowed ground is often where the web of time is at its weakest.

However, upon scanning the arch Sarah finds nothing out of the ordinary. Barbara again presses Rani for information about who she thinks Sarah, or rather Victoria, really is. Suddenly the Trickster begins to manifest in the archway, and Barbara is horrified, but before she can see what is really happening Eddie arrives and drags her back to the village hall. Soon both she and Eddie realise that all the odd goings-on are because of them, for everything they touch – such as fruit and flowers – begins to die.

The Trickster grows stronger in the gateway, but Sarah is determined to block the transference with her Sonic Lipstick. However, the Trickster claims that technology is useless in trying to stop him and Luke agrees – there is only one way to stop him manifesting, and Sarah has known this all along. She protests again but Luke insists she must use the Sonic Lipstick to repair Eddie and Barbara’s car and allow them to die.

In the village hall, Barbara recalls what Rani said in the Abbey about their car, and tells Eddie that by not going in it, as he intended, they have done something bad, allowing the creature under the arch to appear. At last she understands that the woman is not really Victoria – she is their Sarah Jane.

In the town square Sarah repairs the car, but confesses she cannot allow her parents to die. However, Eddie and Barbara arrive with baby Sarah in her pram, having worked out for themselves that if they drive away in their car then they will be able to save the day. Adult Sarah protests but Barbara insists, telling them to look after the baby. Luke realises that Eddie and Barbara did not abandon their child, they saved her.

Before they go, Eddie asks his grown-up daughter what kind of life she has led, and Sarah tells him that it is a life of extraordinary things. Tearfully she embraces her mum and dad, and having found peace with them, and herself, she watches them kiss their baby goodbye and get inside their car to drive away to their fates.

Once they are gone the storm raging around them stops, and the half-formed Trickster appears beside Rani, Luke and Sarah, evidently in pain. He claims Sarah has denied him his hunger, but she tells him it was her parents who saved the day – they sacrificed themselves rather than let their daughter convince them. Defeated, the Trickster screeches and turns to dust. Luke then tells his mother that to put time on its correct path they must leave baby Sarah alone.

In the alternate future Clyde and the Graske realise that history is about to revert, and, clutching the box for safety, they wait for time to correct itself. Soon they are back in the abandoned shop where everything began, and true to his word Clyde hands over the metallic box to the Graske, thereby granting him his freedom. As the creature teleports away Clyde turns to the area where the Fissure once opened up.

In the field where the Fissure originally appeared, Sarah, Luke and Rani gather, taking one last look at the village before opening the portal and stepping through to the present, where Clyde is waiting for them. Sarah decides that the Fissure must now be closed forever, and after sealing it she stamps on the Converter so that it will not be used again. That done, she returns home with her friends.

On Bannerman Road Rani is jubilant when her mum and dad arrive to greet her; happy she has them back again. The reunited family go back across the road and Clyde follows suit, wandering home, now in the knowledge that the life he and the others leave can sometimes bring them the best of things, and sometimes the worst.

ome time later, up in the attic, Sarah looks again at the one photograph she has of her parents, and then breaks down in tears. Holding Luke for comfort Sarah recalls how brilliant they were, and Luke confesses he now appreciates how lucky he is to have Sarah as a mother. The two embrace once more, whilst the photograph, now turned over, reveals the legacy of Barbara and Eddie Smith – the last of their messages to each other: