Thomas Cale - the world's most dangerous yet reluctant hero - has been running from his enemies. Tracked down moments before his execution, Cale is presented with a chance to escape.

But it comes at a price: He must murder the American president. The father of modern democracy. The man fighting the south's attempts to reinstate slavery.

Accept, and he risks the fates of millions.

Refuse, and he endangers his own life . . .