If you were disappointed that the CW’s big ”Heroes v Aliens” crossover technically began Monday with a Supergirl episode that was 98.9 percent crossover free, last night’s second chapter more than made up for it, resulting in a hell of a watch and what is easily the best episode of The Flash this season.
Source: io9 – The DC/CW Crossover Finally Kicked Off, and It Was Totally Worth the Wait