The Doctor and the Master must make an uneasy alliance to overcome a common enemy, the Sild, which have been attacking the Earth and using the Master as their tool of conquest. With the Brigadier, UNIT, and others gradually forgetting who the Master is, the Doctor and the Master must defeat the Sild before the Master becomes unstitched from time and the Earth is overrun by the vicious Sild. The events of the novel take place at some point after
The Dæmons and before
The Sea Devils; settings include a North Sea oil rig and a distant planet in a very distant future. ==See also==