"It's not malaria. At least, no strain that I'm familiar with."
From the moment that the Doctor and Leela leave the TARDIS, they know that something is very definitely wrong in a small seaside town in France.
An old woman nurses the madness in her mind... and the alien infestation in her body. Her son has lost his sanity — in accordance with the plans of a secret society. An androgynous alien pursues a vendetta against a hyperdimensional arms dealer who's stolen hir birthright. A pair of businessmen in Paris prepare to close a deal with an approaching fleet of spacecraft which will result in the transfiguration and slavery of hundreds — and the deaths of millions.
Can the Doctor work out who's on which side, before they all kill him... even the butler?