Lionsgate has captured the theatrical rights to Ryan Reynolds coffin movie Buried, which features one of Hollywood’s hottest stars trapped in a box for the duration of the film. The purchase, valued between $3 million and $4 million plus a significant marketing commitment, marks the second deal at the Sundance film festival. The first was Paramount’s purchase of the Davis Guggenheim documentary Waiting for Superman. At the close of the Sundance festival’s first weekend, many films, such as Josh Radnor’s Happythankyoumoreplease and the Ben Affleck-starrer The Company Men, have garnered solid buzz, but there are no deals yet to accompany interest in those movies.

Buried, from Spanish director Rodrigo Cortes centers on Paul Conroy, a U.S. truck driver stationed in Iraq, who wakes up to find himself buried alive inside a coffin. His captors have given him two tools: a lighter and a cell phone, to meet their $5 million ransom demand before he runs out of oxygen. (Check out the trailer to see why this high-concept thriller, which can easily be explained on a one-sheet, sold so quickly.)

Fans were wild about the film after its first screening late Saturday night. So, it seems, were executives. “Buried is one of the tightest, most intense thrillers we’ve ever seen,” says Jason Constantine, Lionsgate’s president of acquisitions. “It’s a powerful reminder that all you really need for an unforgettable movie experience is a great story, inventive filmmaking and brilliant acting.” The studio hasn’t yet settled on a release date.

More from EW at Sundance 2010:

Owen Gleiberman’s Sundance 2010 Critic’s Notebook:

The Runaways: Kristen Stewart and Dakota Fanning rock out

Sundance 2010 documentaries: Casino Jack and the United States of Money; Smash His Camera; Restrepo

The Company Men: A juicy drama of downsized corporate executives

Howl and Nowhere Boy: The fascinating early days of Allen Ginsberg and John Lennon

Sundance 2010: Change you can believe in?