Oliver (Stephen Amell) discovers a man who goes by the name "The Mayor" (guest star Cle Bennett) is bringing illegal guns in to The Glades, so Oliver sponsors a "Cash for Guns" event to help clean up the city. Unfortunately, The Mayor crashes the event with his gang and seriously injures Sin (guest star Bex Taylor-Klaus). The Canary (Caity Lotz) is furious when she learns her friend is in the hospital and sets out for revenge. Meanwhile, Felicity (Emily Bett Rickards) stuns Oliver with a bit of information about the Canary, Donner (guest star Dylan Bruce) asks Laurel (Katie Cassidy) to dinner, and Diggle (David Ramsey) reconnects with an old friend.
