Arrow’s 100th Episode and Crossover Event Synopsis’

Arrow’s 100th episode is scheduled to air on November 30. The episode week features a series of crossover events: Supergirl, “Medusa” (airing Monday, Nov. 28) The epic superhero crossover kicks off tonight when Barry Allen (guest star Grant Gustin) and Cisco Ramon (guest star Carlos Valdes) seek Kara’s help with an…