The Flash A crossover involving all four of the CW’s superhero series continues in Central City when the Dominators arrive and Barry (Grant Gustin) seeks help from Green Arrow (Stephen Amell) and the Legends of Tomorrow, before Supergirl (Melissa Benoist) joins the battle. 8 p.m. KTLA
The Middle Axl (Charlie McDermott) stopped speaking to Frankie (Patricia Heaton) after she told him what she thinks about his new girlfriend. Atticus Shaffer, Eden Sher and Neil Flynn also star. 8 p.m. ABC
Brooklyn Nine-Nine Terry (Terry Crews) is a big fan of an author (guest star Fred Melamed)...