In addition to balancing action and drama, another thing the show does well is writing in lines of dialogue that fit perfectly in a scene, but stick out just enough to make a viewer question their inclusion. The fact that her sister may soon appear from beyond the grave certainly won't help matters.
(It's also interesting to note that Arrow was rather keen on the Public Service Announcements this time around: gun violence, dangers of drinking and driving, and even Amell appearing in an actual PSA during the break about the problem of texting and driving.) Everyone else has gotten their lives together, so of course we'll have to watch as Laurel's falls apart. Speaking of drama, what is going on with Laurel? Granted, she has a lot to be upset over, but it's interesting that the writers are pushing her into a possible drug and alcohol problem. The action scenes are always entertaining and it's nice when their quality is matched by the dramatic interactions during the rest of the hour. While she recovers in the hospital, Canary and Arrow team up to take The Mayor down in a fun fight sequence that features Arrow shooting a grenade out of the air and both heroes switching weapons mid-fight. Unfortunately, the trade-in event gets lit up by The Mayor himself (where the local cops prove completely useless), and Sin ( Bex Taylor-Klaus) gets shot in the process. At the same time, Arrow and his team track the weapon supply to a local military base thanks to one of Diggle's informants (and possible love interest?). To move the plot along, Oliver sponsors a "Cash 4 Guns" trade event to get the weapons out of the Glades. This bit comes into play later on, as well. Oliver then reveals to Diggle and Felicity that he saw Sara a year after the sinking of the Gambit. In a big reveal (that was unfortunately spoiled for myself and many others by IMDb's cast listing), Black Canary is in fact Sara Lance ( Caity Lotz), the sister of Laurel who accompanied Oliver on his ill-fated voyage on the Gambit, and was presumed lost at sea. More interesting than The Mayor is Black Canary who, it turns out, is following Laurel, allowing Arrow to track her down and interrogate her. What happens to him by episode's end, however, is worth noting. The Mayor isn't very interesting as he amounts to nothing more than a jumped-up thug. This cold open establishes everything we need to know about this particular episode's plot right out of the gates, including the new enemy of the week, The Mayor ( Clé Bennett). Laurel ( Katie Cassidy) attends with Sebastian Blood ( Kevin Alejandro). Arrow and Diggle ( David Ramsey) discuss the stolen weapons in the gang's possession. During a soiree at the Queen family mansion, Arrow ( Stephen Amell) cleans up some gun-toting criminals in the Glade while Felicity ( Emily Bett Rickards) stalls Oliver's guests, including hostile CEO Isabel Rochev ( Summer Glau).