...Agatha standing at the Harrogate Hotel entrance, looking at the Doctor and Donna in confusion... And my son. And, at the same time (flashback of Lady Eddison reading "The murder of Roger Ackroyd" in the library) it absorbed the works of Agatha Christie, directly from Lady Eddison. DOCTOR: It's the day Agatha Christie disappeared. DOCTOR: The Eddison title descends through her. DOCTOR: Which means, one of that lot is an alien in human form. Donna snatches the Firestone off Agatha and throws it into the lake, the Vespiform chasing after it, drowning in a purple glow. GREEVES: May I announce, Lady Clemency Eddison. It's a Vespiform telepathic recorder! Purple light surrounds the Reverend while he transforms into the Vespiform. REVEREND: This is supposed to be a party! Solving a murder mystery with Agatha Christie, brilliant! The Doctor and Donna follow her with the other car. The Doctor looks at Reverend Golightly who stares back, confused. The amnesia! The cars stop at the Silent Pool lake. The wasp, the murders...
DONNA: And us! There's a murder, a mystery, and Agatha Christie. They find that most of the people didn't leave the dining room: Robina is sitting in astonishment, gasping, the Colonel is topsy-turvy on his wheelchair, Lady Eddison is at the head of the table, Davenport is on the ground, and the Reverend is to the side of the room. We see Christopher becoming a giant wasp. Where?
Plan: A: The Doctor; Q: Who realizes that they have arrived on the day Agatha Christie disappears? A: Donna; Q: Who throws the necklace into the Silent Pool? A: a dinner party; Q: What do the Doctor and Donna invite themselves to in 1926? A: human form; Q: What form does the Vespiform take? A: Vespiform; Q: What is the name of the giant shapeshifting alien wasp that kills three of the guests? A: Lady Eddison's illegitimate half-human son; Q: Who is Reverend Golightly? A: a telepathic link; Q: What does Golightly have with Lady Eddison? A: the details; Q: What did Golightly absorb from The Murder of Roger Ackroyd? A: The Murder of Roger Ackroyd; Q: What Agatha Christie murder mystery was Reverend Golightly reading? A: his mother; Q: Who was reading The Murder of Roger Ackroyd when Reverend Golightly became aware of his alien nature? A: drowns; Q: What happens to the wasp when he dives after Donna's necklace? A: amnesia; Q: What does Agatha suffer from after she falls unconscious? A: the Doctor; Q: Who drops off Agatha at the Harrogate Hotel? A: the Harrogate Hotel; Q: Where does the Doctor drop off Agatha Christie after she suffers amnesia? Summary: The Doctor and Donna invite themselves to a dinner party in 1926, hosted by Lady Clemency Eddison and Hugh Curbishley, where one of the guests is Agatha Christie . The Doctor realises that they have arrived on the day Agatha inexplicably disappears. A giant shapeshifting alien wasp in human form called a Vespiform kills three of the guests with methods similar to the murders in Agatha's murder mysteries. The Vespiform is revealed to be Lady Eddison's illegitimate half-human son, Reverend Golightly. Golightly, who has a telepathic link with Lady Eddison through her necklace, became aware of his alien nature and absorbed the details of The Murder of Roger Ackroyd , an Agatha Christie murder mystery his mother was reading at the time. He transforms into the Vespiform and threatens the guests. Agatha lures him towards the Silent Pool . Donna throws the necklace into the water, and the wasp dives after it and drowns. Due to her own connection with the necklace, Agatha falls unconscious and suffers from amnesia . This becomes the event that gave her the amnesia during her disappearance, and the Doctor drops her off at the Harrogate Hotel .