The true story of an FBI undercover agent (Johnny Depp) who becomes Donnie Brasco, 'The Jewel Man', to infiltrate one of the mob families.

Donnie manoeuvres his way into the confidence of ageing hit man, Lefty Ruggiero (Al Pacino) who trusts Donnie and vouches for him to the mob. But Lefty and Donnie become friends when they should be enemies.

As Donnie moves deeper and deeper into the Mafia chain of command, he realises he is not only crossing the line between federal agent and criminal but it also leading his friend Lefty to an almost certain death sentence...