17 year old Tess travels to London to meet her father, who arrives in town from out of the country, for three days of fun. Things do not go as to plan.
Room 13 is gone, and Tess' father along with it. The problem is, no one believes Tess, and she has precious little evidence to support her claim that he and his hotel room have both mysteriously vanished.
Unaware that the room is bugged, Ingrid warns Tess and tells her the truth. On her way home, Ingrid is waylaid and shoved into the back of a van. Meanwhile, her father's captors spirit him away.
Max meets Vicky, who has received a mysterious package from Dr. Buscombe, which she gives to Tess for safekeeping. A bit of sabotage providing a diversion, Max and Tess find out the truth about Room 13.
Tess and Max break into Room 13, where they uncover evidence. The colonel interrogates Dr. Bascombe. In their quest for the Passinetti papers, the Secret Police agents kidnap Vicky for questioning.
Tess and Max are left bound and gagged, while the Colonel and his henchmen plan to flee the country. Vicky tricks her guard. Tess escapes and races to save her father.
