Sarah Jane, Clyde, and Rani are sent to three different time periods to retrieve three different MacGuffins.
Sarah Jane, Clyde, and Rani go to a shop to investigate a possible alien sighting they saw in a newspaper clipping. There they meet the Shopkeeper and his parrot, which he calls Captain. The Shopkeeper put that article in the paper to bring Sarah Jane and her friends to the shop. He tells them that they must go to three different time periods to retrieve three objects made of a metal called chronosteel. Chronosteel is a metal forged in the Time Vortex and has the power to alter history, which would cause the whole planet to be sucked into the vortex. Once the three pieces of chronosteel are brought into the same time period, the danger passes. However, they must bring the chronosteel into the present in a certain period of time. He sends the three of them through a "time window" without waiting for their permission.
Rani is sent to the Tower of London in 1553, where the young Lady Jane Grey has been Queen for only a few days. Mary, a Catholic, is sending her army into London to capture the Protestant Jane, who she considers a usurper. Rani is mistaken for a new-lady in-waiting and befriends Jane. Matilda, one of Jane's servants, attempts to assassinate her with a dagger made of chronosteel but Rani stops her. Matilda claims that she is a Protestant, like Jane, who hoped that Jane's death as a martyr would inspire England's Protestants to rise up against Mary. Instead, Jane will die quietly like a common criminal. Rani could return home by touching the chronosteel but instead stays to comfort Lady Jane, to the Shopkeeper's dismay. Thankful to her friend, Jane gives Rani permission to return home. Rani picks up the dagger and returns to the present. Jane mistakes Rani for an angel.
Clyde is transported to an English coastal village in 1941. He meets a local boy named George and the two of them spot a small group of SS troops, led by Lt. Koenig, on the beach. They hide in a church but are found by the Nazis and taken prisoner. Koenig reveals that they possess a piece of chronosteel, which he believes to be Thor's hammer. The power of the chronosteel will allow them to interfere with Britain's radar systems and launch an invasion. Clyde warns Koenig that his tendency to underestimate anyone different from him will be their downfall. George and Clyde escape when Clyde fools the Nazis into thinking his cell phone is a bomb. They ring the church bell, bringing in the Home Guard who capture Koenig and his men. George expresses eagerness to sign up for the war. Clyde, worried about his friend, suggests that he wait until 1945 but George refuses. After telling George to be careful, Clyde takes the chronosteel and returns to the present.
Sarah Jane is sent to a house in 1889, where she meets Emily Morris, a ghost hunter. Sarah Jane proves to Emily that she is from the future by giving her the newspaper clipping. Emily says that at eight o'clock each night, a series of strange sounds and voices come from the house. They hear a woman, a babysitter, sneaking out of the house to visit her boyfriend. To keep the kids safe, she locks them into their bedroom. When one of the children lights a candle, it starts a fire which kills the children, who cannot get out of the room. When Sarah Jane hears modern slang, she realizes that the voices are not ghosts but glimpses of the future. Resetting the clock to eight, Sarah Jane and Emily hear the events over again. While the door is locked in the future, the key still exists in Emily's time period. She opens the door, allowing the children to escape as their house burns. Sarah Jane takes the key, opening the time window. However, Emily refuses to let her take it, wanting to know more about the future, and Sarah Jane is sucked through the time window without the key.
Back in the present, the Earth is about to be sucked into the time vortex. At the last moment, a woman named Angela enters the shop with the key and the crisis is averted. Angela is Emily's granddaughter and found Sarah Jane through the newspaper clipping she had left with Emily. Sarah Jane and Angela go out for coffee to discuss Emily. Clyde learns that George was recently knighted for his work on radar technology. Rani researches Lady Jane, who died peaceful and content.
- The Bad Guy Wins: Just barely averted in the World War II time frame.
- Chekhov's Gun: The newspaper article from the present. Sarah Jane shows it to Emily to prove she's from the future and her granddaughter Angela shows it as proof.
- Continuity Nod: the atmosphere is similar in general in Sarah Jane's subplot, but the moving of the clock hands looks like a specific reference to "Ghost Light".
- Dismantled MacGuffin: While they're not actually pieces of the same artefact, the pieces of chronosteel must be brought together into the same time period to stop them from destroying the universe.
- False Flag Operation: Matilda plans to assassinate Lady Jane Grey and frame the Catholics.
- Historical Domain Character: Lady Jane Grey.
- The Mole: The schoolteacher in the WWII story. Lady Matilda is mistaken for one, but she's actually a Well-Intentioned Extremist.
- Mythology Gag: Sarah Jane's newspaper clipping is dated November 23, 2010, 47 years to the day after its parent show premiered.
- Newspaper Dating: Inverted; Sarah Jane shows Emily in 1889 that she's been taken from 2010 using a newspaper clipping she was holding.
- No Equal-Opportunity Time Travel: Mostly averted. Clyde experiences some racism, but only from Nazis and one British traitor. The white British boy he befriends treats him fairly. Rani also quickly gains acceptance as Lady Jane Grey's new lady in waiting, with only one mention that she has "travelled from afar" and is from "the court of the Taj Mahal".
- San Dimas Time
- Ship Tease: Rani confides in the married teenage Queen Jane that she does have a male friend, building on the affection that has formed between her and Clyde through the episodes of the series.
- Well-Intentioned Extremist: Lady Matilda, who wants to martyr her queen to foment a Protestant uprising.