Within its basic parameters... it's tautly effective.

The two-step between Gordon-Levitt and Austrian newcomer Memar as their respective plights shift and evolve is more pleasingly naturalistic than one might expect.

The ending, however, is also the film's weak spot and consistently flirts with Stockholm syndrome silliness. By then, however, sweaty, nerve-shredded and palpitating, you'll just be glad to be back on terra firma.

Outside of [Joseph Gordon-Levitt], nobody else had a notably good performance.