The CW's "Arrow" and "The Flash" crossover episode "Flash vs. Arrow", is directed by Glen Winter, from a story by Greg Berlanti, Andrew Kreisberg and teleplay by Ben Sokolowski, Brooke Eikmeier, airing December 2, 2014:
"...'Barry' (Grant Gustin) is thrilled when 'Oliver' (Stephen Amell), 'Felicity' (Emily Bett Rickards) and 'Diggle' (David Ramsey) come to 'Central City' to investigate a case involving a deadly boomerang.
"Excited about teaming up with his friend, Barry asks Oliver if he’d like to help him stop 'Ray Bivolo' (Patrick Sabongui), the meta-human Barry is currently tracking. Bivolo causes people to lose control of their emotions and has been using that skill to rob banks. Unfortunately, the superhero partnership doesn’t go as smoothly as Barry expected.
"When Oliver tells Barry he still has a lot to learn, Barry sets out to prove him wrong by attempting to stop Bivolo alone. However Bivolo infects Barry and sets him on a 'rage rampage', with everyone in danger..."
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