Time Out says
Daniel Radcliffe gives a terrific performance as an FBI analyst undercover with white supremacists
Daniel Radcliffe does his best work to date as an idealistic young FBI agent who infiltrates a group of white supremacists in this otherwise standard-issue thriller inspired by real events. He plays Nate Taylor, a nerdy desk analyst ordered to shave his head and go deep undercover to discover which neo-Nazi leader is attempting to build a dirty bomb. Is it the hate-spewing shock jock (Tracy Letts)? The terrifying man-mountain Aryan Alliance leader (Chris Sullivan)? Or a clean-living, teetotal racist who puts up swastika bunting for his family barbecues (Sam Trammell)?
There’s nothing terribly original about ‘Imperium’; it’s not tough enough or tense enough, and there’s an air of faking-it hanging over a lot of it (‘Romper Stomper’ and ‘American History X’ told similar stories with greater impact). But it is solid and watchable, and Radcliffe is genuinely ace, giving a smart, understated and intelligent performance.
Cast and crew