Sir Jeremy HodgeEdit
Shortly after the launch of the Sun Probe mission, Lady Penelope is asked to meet her friend, Sir Jeremy, at a small café in Paris. He reveals that Sun Probe is powered by a revolutionary new fuel extracted from sea water, the recipe of which is top secret. Sir Jeremy worked closely on the project along with a certain Professor Borender. After the launch of Sun Probe, however, the Professor was en route to a science conference in Paris to discuss his work when he mysteriously disappeared. Sir Jeremy was supposed to meet him at Anderbad station, but despite having testimonies that he boarded the train at Paris the Professor was not on the train by the time it arrived. Sir Jeremy asks for International Rescue's help finding Professor Borender, fearing that he has been kidnapped and knowing that the rocket fuel formula could be dangerous in the wrong hands. Lady Penelope agrees to help: Sir Jeremy helped establish the International Rescue organisation and they consequently owe him a debt of gratitude.
During their meeting, Lady Penelope raises her glass to take a sip of her Pernod, but Parker shoots the glass from her hand with one of FAB 1's headlight guns before she can have a drink. He informs her that the drink was drugged as a shady stranger hurries from the café. While the waiter stammers an apology, Penelope searches the seat vacated by the stranger and finds a book of matches bearing an unfamiliar crest.
Trip to a Deadly BasementEdit
The next day, Lady Penelope and Sir Jeremy visit a herald to determine the origin of the crest and hopefully establish the identity of their mysterious stalker. They go down into the basement to search the records, unaware that the herald is the stranger in disguise. They find the crest in a book of records, but the accompanying text has been torn from the book. At that moment, the basement door slams shut and the room begins to fill with gas. Penelope calls Parker, who confirms that the man leaving the office is Penelope's assailant from the café. Rather than sending him in pursuit, Penelope asks Parker to help them escape. Parker uses FAB 1's grapples to tear out the basement door.
Tracing the Professor's StepsEdit
Having reached a dead end in their enquiries, Penelope and Sir Jeremy decide to retrace the Professor's steps and board the overnight monotrain from Paris to Anderbad. Parker in FAB 1 takes the road to Anderbad, while Virgil, Alan and Gordon in Thunderbird 2 watch over the train as it leaves the Anderbad Tunnel. The staff aboard the train deny all knowledge of Professor Borender's presence, but Penelope later receives a note with her tea, saying "Beware -- you are dealing with desperate men". Their steward soon disappears, thrown from the train by the stranger from the café, who poses in his place as the new steward. When the train goes through the Anderbad Tunnel the next day, it is brought to a halt by a power failure, and the stranger orders Lady Penelope and Sir Jeremy to follow him off the train.
The Anderbad TunnelEdit
Meanwhile, in Thunderbird 2, Virgil and Gordon are concerned at the amount of time the train is taking to leave the tunnel, but eventually observe its exit. When they are informed by Parker that Lady Penelope and Sir Jeremy are no longer aboard, they unload the Monobrake from the pod and go back through the tunnel.
They soon find that the pair are being held hostage by a rival scientist called Dr Godber who has held Professor Borender but failed to extract from him the rocket fuel formula. To persuade him, the scientist has placed Lady Penelope on a ladder across the tracks to be killed when the approaching Anderbad Express passes through the tunnel unless the Professor shares the secret.Gordon attacks in an attempt to disable the scientist while Virgil tries to free Penelope. In the ensuing firefight, Godber's henchman Roache (who is operating the control system) sees that Godber's plan has gone too far and tries to stop the train using the controls but Godber upon seeing Roache betraying him. fires and kills him and then shoots the control panel, meaning that Virgil's only option is to sever the cable suspending Penelope in front of the train. He succeeds at the last second and the train speeds safely overhead while Gordon shoots the scientist's gun from his hand.
Back in ParisEdit
That evening, Alan visits the café with Penelope and Sir Jeremy, lamenting the fact that his brothers have left him to go to a club. His misery turns to joy when Parker arrives with Tin-Tin, who will join them for the night. Penelope hesitates to drink her Pernod, remembering what happened last time she tried to take a sip. With Sir Jeremy's persuasion, however, she raises her glass as a firework display lights up the Parisian sky.