England, 1540. Out of favour with Thomas Cromwell, Matthew Shardlake is intent on keeping a low profile in the courts. But his involvement with a murder case, defending a girl accused of brutally killing her young cousin, brings him once again into contact with the King’s chief minister – and a new assignment . . .

The secret of Greek Fire, the legendary substance with which the Byzantines destroyed the Arab navies, has been lost for centuries. Now an official of the Court of Augmentations has discovered the formula in the library of a dissolved monastery. When Shardlake is sent to recover it, he finds the official and his alchemist brother brutally murdered – the formula gone.

Now Shardlake must follow the trail of Greek Fire across Tudor London, while still trying to prove his young client’s innocence. But very soon he discovers nothing is as it seems . . .

This is the second novel in C. J. Sansom's gripping historical series. It is followed by Sovereign, the third book in the series.