This is one of those haunted house mysteries where the mysterious, potentially dangerous disturbances turn out to be the work of gangsters who want the empty mansion for their own gambling enterprises. Meanwhile Frank and his buddies, who use the place for band practice, keep picking and frailing right through the cherry bombs and falling plaster. . . until someone starts shooting at them. And all the time they imagine that they can hear Bob, their mandolin player who was killed in a car accident, playing along with them. Glib, but the old-timey bluegrass sound makes an upbeat background.