Skiing at a Big Bear resort are Dr. Lanson, an atomic scientist, Ted Noland, Donna Weeks and her unscrupulous sister Peggy. Also there are Joan Cochran, Burke and Johnny, young communists out to steal Lanson's papers. As they plot and scheme, a romance develops between Donna and Ralph Payne, a F.B.I agent on a skiing vacation. Nolan, working with the communists, kills Lanson after the latter discovers him copying his papers. The killing is witnessed by Peggy, who snatches the plans while Noland is making it appear that Lanson died in a skiing accident. Paul Malone, Payne's supervisor, and Sheriff Bowman enter the investigation.