Blood Debt (Victor the Assassin, #11) by Tom Wood

They want an eye for an eye. He'll fight until the last drop is spilled.

The incredible latest novel in the most visceral, action-packed series around sees the assassin Victor fighting enemies on all sides, with no allies in sight.

To make amends for past mistakes, the enigmatic assassin known only as Victor is now in servitude to the world's most dangerous criminal enterprise, the Russian Mafia. Although a hired gun without loyalties, Victor never picks a fight he cannot win so he intends to pay off his debt, however long it takes.

Yet when his new employer is shot dead in London, Victor has both the means and the motive to make him the most likely suspect. With a turf war breaking out in the power vacuum, and enemies on all sides, either Victor discovers who the real murderer is or suffer the full wrath of the Mafia's vengeance.