In the first part of the epic crossover event with The Flash and Arrow, Barry is thrilled when Oliver (guest star Stephen Amell), Felicity (guest star Emily Bett Rickards) and Diggle (guest star 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 Roy Bivolo (guest star Paul Anthony), 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, when Bivolo infects Barry and sets him on a raging rampage, everyone is in danger, and the only one who can stop him is the Arrow.
When a metahuman named Ray Bivolo -- who causes people to lose control of their emotions -- infects The Flash, Arrow and his team heads over to Central City to save the place.
Jesse Warn, Glen Winter
Danielle Panabaker, Jesse L. Martin, Katie Cassidy, Willa Holland, David Ramsey, Candice Patton, Carlos Valdes, Colton Haynes, Rick Cosnett, John Barrowman, Stephen Amell, Tom Cavanagh, Paul Blackthrone, Emily Bett Rickards, Grant Gustin