The Doctor answers a psionic distress call being sent from England in the 1920s. There, in the environs of a fairground, he is reunited with an old friend: Harry Houdini. To Adric and Nyssa the name means very little, but to the Doctor's companion Tegan he is a legend. Escape artist extraordinaire, Houdini's reputation will last for decades.
But how come Harry knows so much about Tegan herself? Is it really just guesswork, as he says? Is Harry right to be concerned about the fairground's fortune teller, who claims to have supernatural skills? Both he and the Doctor suspect an alien influence they know of old.
What neither the Doctor nor his friends realise is that, somewhere in the shadows, a far more sinister and familiar presence is lying in wait for them...
While attempting to take Tegan to Heathrow airport for her flight attendant job, the Doctor diverts to London in the 1920s. Tegan, Nyssa and Adric are of the opinion that the Doctor has once again failed to pilot the TARDIS properly, but for once they are wrong; he has followed a psionic distress call received via the telepathic circuits. It leads them to a fairground, and an old and famous friend: Harry Houdini.
Tegan is suitably impressed, and thrilled to meet the renowned escape artist and illusionist. The reference is lost on Nyssa and Adric, but even they are caught up in his charisma; and when he knows more than he should about Tegan, they are intrigued. Houdini plays it off, however, and diverts to another matter: He has come to the fair to debunk its fortune teller, who has inexplicable abilities of her own, but he has not been able to do so. Now he wants the Doctor's help.
Something is not right, though. Houdini seems intent on drawing information from the Doctor which he should not have, regarding his own future and the workings of the TARDIS. Before it can be addressed, however, the group is split up; Houdini and the Doctor go to check out the fortune teller, and the three companions find themselves inside the fair's menagerie.
The Doctor and Houdini don't find the fortune teller, but they do find something else—her crystal ball. It proves to be no ordinary prop. The Doctor recognises it, and refers Harry back to a previous adventure they shared (in the Doctor's first life, along with Ben Jackson and Polly Wright) in which they encountered the Ovids, beings of pure thought. The Ovids used crystal spheres to communicate and influence the world; spheres just like this one. And this one is already in use.
In the menagerie, the companions are menaced by animals that have been released from their cages, including a tiger. Adric runs, leading the tiger away from the others, giving them time to try to escape. Tegan shouts for the Doctor, but to no avail. Adric is rescued, however, by a group of fairground workers and performers; but it is short-lived, as it becomes clear that they are under some kind of mind control. They escort him to a theatre on the grounds. Meanwhile, Nyssa also has an odd encounter, with a man wearing the face of her lost father: The Master. He takes hypnotic control of her, and forces her to abduct Tegan and bring her to the theatre as well.
The Doctor tries to make telepathic contact with the sphere, and is successful, though it hurts him. As he is about to make progress, he is interrupted by the image and voice of a young man wearing a bow tie—the Eleventh Doctor. He tells the Fifth Doctor that he will soon be tempted to destroy the sphere, but he must not. Instead, he must return it to its rightful owners, the Ovids. At the same time, he is interrupted by Tegan's scream, which the sphere has also picked up; he realises that they are in danger, and he has failed to help them.
The Doctor and Houdini hurry toward the theatre; but Houdini attacks him and takes him captive. He places the Doctor inside a crate that is intended to be used in his famous underwater escape trick, and tells him that he has met an old friend of the Doctor, who revealed to him that the Doctor has manipulated him and withheld information. It's all a lie, of course; and the Doctor recognises the source as the Master. Nevertheless, in an effort to persuade the Doctor to tell him more, Houdini pushes the crate into the water... and watches as the Doctor fails to escape.
On the theatre's stage, Adric is seized by the Master, but he cannot see him. In the struggle, he sees a mirror propped up on the stage, and realises that the Master is visible in the mirror, and their reflections are struggling. It defies science, but there's little time to think about it, as he struggles to break free. Tegan intervenes, and sees the situation, and starts to throw a chair to break the mirror; Adric shouts at her to stop, not knowing what effect it may have on him. Instead, she throws the chair at the spotlight that is trained on the mirror, creating the reflections; it breaks, and the Master vanishes.
All is not saved, though. Enraged, the Master starts to use the Ovid sphere to release massive amounts of electricity through the fairground, setting things on fire and destroying buildings. Houdini catches up with the companions as they try to escape, but they are cut off. Suddenly the Doctor returns, and reveals that he picked Harry's pockets for his lockpicking kit, using that—and his Time Lord ability to bypass respiration—to escape the trap. He had suspected Harry was not himself all along. They make their way back to the fortune teller's booth, the Doctor explaining that the Master was never corporeally there at all; he seems to be still trapped in the collapsing dimension where they last saw him. Instead he was using the sphere to exert his will remotely, and even project himself. He locates the sphere, and is tempted to destroy it—just as promised—but instead, he makes contact with it to try to soothe it and end the energy discharge. It isn't enough, however, and Tegan joins the link, adding her own thoughts to bring the crisis to an end.
As the smoke clears, the fairground workers awaken from their trance, having no memory of the last twelve hours. Houdini convinces them they have been unwitting participants in an experimental new act, which seems to satisfy them. He again attempts to persuade the Doctor to let him see inside the TARDIS, but is gently rebuffed, and admits that it's better to make his future than to know it. As the Doctor and companions leave, Tegan again asks to be taken to Heathrow, but the Doctor tells her they must first make a stop: to return the sphere to the Ovids.
- Nyssa and Adric consider the fairground carousel to be rather frivolous and silly.
- Harry Houdini has met the Doctor on several previous occasions and is aware of regeneration. As he once met Jo Grant, one of these encounters took place during his third incarnation. He learned of the existence of the Bay City Rollers from Jo.
- The Ovids are beings of pure thought who travel from world to world in crystal spheres. Four of them became trapped in New York City in the 1890s. They can give form to dreams and nightmares. Houdini helped the First Doctor, Ben Jackson and Polly Wright free the Ovids.
- There were no zoos on Traken.
- There is a tiger and a leopard in the fairground menagerie.
- The Doctor receives a message from his eleventh incarnation through an Ovid sphere. He realises that it is his future self.
- The Master refers to Adric, Nyssa and Tegan as "the Doctor's whelps."
- Excluding his brief off screen appearance in Circular Time: Winter, this is the first Fifth Doctor audio drama to feature the Master.
- This audio drama was recorded on 17 December 2012.
- Tegan is still wearing her Air Australia uniform. (TV: Logopolis, Castrovalva, Four to Doomsday, Kinda, The Visitation)
- The Doctor has once again failed to return Tegan to Heathrow Airport in 1981. (TV: Four to Doomsday, Kinda, The Visitation)
- Houdini tells Tegan that her aunt Vanessa would be proud of her as she had always wanted to travel. (TV: Logopolis)
- The Doctor also encountered Houdini in his first (PROSE: Houdini and The Space Cuckoos), eighth (PROSE: The Great Escapes) and eleventh (PROSE: Houdini and The Space Cuckoos) incarnations. From Houdini's point of view, the latter was the first encounter with the Doctor. However, he fails to recognise the Eleventh Doctor on this occasion.
- The Doctor's sonic screwdriver was recently destroyed by the Terileptil leader in London in September 1666. (TV: The Visitation)
- Nyssa refers to the Fourth Doctor's recent regeneration. (TV: Logopolis)
- Tegan would later be cornered by another tiger on Lady Adela Forster's private train in Calcutta, British India on 31 December 1926. (AUDIO: The Emerald Tiger)
- The Eleventh Doctor refers to spoilers. (TV: Silence in the Library, Let's Kill Hitler, The Name of the Doctor, The Day of the Doctor)
- The Master refers to Traken's destruction. (TV: Logopolis)
- Nyssa refers to the Master's apparent death on Castrovalva. (TV: Castrovalva)
- Houdini refers to the fact that the Doctor and the Master attended the Time Lord Academy together. (TV: The Sea Devils, The Five Doctors)
- Tegan tells the hypnotised Nyssa that she knows what it is like to be under someone else's control, having been controlled by the Mara on Deva Loka. (TV: Kinda)
- Tegan refers to the Master killing Nyssa's father Tremas and stealing his body (TV: The Keeper of Traken) and killing her aunt Vanessa. (TV: Logopolis)
- The Master is trying to reconstitute his body after being trapped in a collapsing dimension on Castrovalva. (TV: Castrovalva)