For The Doctor and his travelling companions, Peri and Erimem, it's a twisted playground, where reality, morality and sanity no longer apply. Stranded within a dimensional nexus, beset by the molten fury of the Firedbreed, they must unwrap a terrifying mystery of damaged timelines and dark science... before the corruption of the Axis spreads and reality itself crumbles.

Pitted against a warped and deadly mind, The Doctor faces his own past transgressions, and the very nature of what it is to be a Time Lord.

This story takes place between Planet of Fire and The Caves of Androzani.