This weekend, the B Street Theatre’s Family Series opens Jerry Montoya’s new adaptation of Mary Shelley’s Frankenstein. The script is a play-within-a-play that explores how a 19-year-old Shelley hatched the concept for her landmark 1818 novel during a gathering of prominent literati. When rainy weather intervenes, the group holds a fireside competition to see who can spin the scariest story. Shelley’s clairvoyant contribution—about a scientist who boldly creates life, and later regrets what he’s done—became a cultural icon. 1 p.m. and 4 p.m. Saturday and Sunday, $15-20. B Street Theatre, 2711 B Street; (916) 443-5300; www.bstreettheatre.org. Through March 20.