Sergeant Richard Sharpe witnesses a murderous act of treachery by an English officer who has defected from the East India Company to join the mercenary army of the Mahratta Confederation.

In the hunt for the renegade Englishman, he penetrates deep into the enemy's territory where he faces temptations more subtle than he has ever dreamed of. And behind him, relentlessly stalking him, comes his worst enemy, the baleful, twitching SergeantObadiah Hakeswill who is determined to break Sharpe once and for all.

The paths of treachery all lead to the small village of Assaye where Sir Arthur Wellesley, with a tiny British army, faces the Mahratta horde. Outnumbered and outgunned, Wellesley decides to fight, and Sharpe is plunged into a battle that will make Wellesley's reputation. It will make Sharpe's name to, but only if he can survive the carnage, for it is at Assaye that he at last realizes his ambition and has a chance to seize it.

The novel culminates in the Battle of Assaye, which Wellington considered his greatest victory.