CW | 8:00 pm
Susan Walters guest stars as the medically savvy mother of Caitlin (Danielle Panabaker), who needs Mom’s help in grasping her transformation, in "Monster." The reunion doesn’t go well, though, since the elder woman has something less than a personal touch in dealing with her daughter. Barry (Grant Gustin) wants to join Julian (Tom Felton) in investigating the latest meta-human to cause problems in Central City. Jesse L. Martin also stars.