There is a scene somewhere in the middle of "Double Dynamite" where Frank Sinatra and Jane Russel are lying on their beds in two rooms separated only by a thin wall and start singing to each other; the camera lingers on Jane's face and smile, and it's a delightful moment. The rest of the movie is not quite on that level, but the three stars make it worth watching anyway: Sinatra is likable, Russell is dazzling, and Groucho Marx has some laugh-out-loud zingers ("You're getting married? Where is the ceremony taking place, Alkatraz?"), and does some of his trademarked eyebrow-raising as well. In fact, I would say that this is a better showcase for him than the Marx Brothers' last film "Love Happy", in which he was essentially just a guest star. "Double Dynamite" is a minor film, but it passes the time very easily. (**1/2)