Summoned back to Gallifrey, the Doctor is framed for the assassination of the Time Lord President. To prove his innocence, he must stand for election himself, uncover the traitor in the Time Lord High Council, fight a hooded killer in a nightmare cyberspace world of his enemy's devising and battle against an old foe now out to destroy the Time Lords: The Master.
While taking in the sights of Paris in 1979, the Doctor and Romana sense that someone is tampering with time. Who is the mysterious Count Scarlioni? Why does he seem to have counterparts scattered through time? And just how many copies of the Mona Lisa did Leonardo da Vinci paint?
When the TARDIS lands in a quarry on Earth, Sarah unearths what appears to be a fossilised hand, buried in one-hundred-fifty-million-year-old strata. Analysis shows the hand to be silicon-based and inert, but when Sarah begins to act as if possessed, the Doctor suspects that it may still be alive...
