AD75. Marcus Didius Falco, once a common informer, now middle class, discovers that newly acquired rank brings associated problems, the most gruesome of which is a corpse buried under the tiles of his new bath house. The contractors have fled to Britain whence, as the Fates have it, Falco is ordered. A local chief and ally of the Romans is having a Palace built by the Emperor Vespasian. However the project is running late, work is slipshod, and fatal accidents keep happening. Somewhere on site are the murderers who may be behind this latest spate of killings. Somewhere in the forefront, trouble-shooting for the Emperor is Falco, without an ally and now next on the list for assassination.