After Oliver killed the original Count Vertigo in season two, it makes sense to see someone else take up the mantle (and very, very clearly state that Oliver has created an enduring name for villain that will always come back to fight him). Werner Zytle's version of Count Vertigo has added a psychotropic component to the drug vertigo, and when he doses Oliver with it he tells him that he will see his greatest fear. Werner's name is direct reference to the Count Vertigo of the comics, though the effects of the new version of vertigo are much closer to the drugs used by Batman villain The Scarecrow. Under the effects of the new vertigo, The Arrow sees Werner as himself, Oliver Queen. Whether Oliver can have both a fulfilling life as Oliver Queen and also be The Arrow was a major theme of season one, and its resurgence here doesn't feel earned. In season one, Oliver was allowed to struggle with being himself and being the vigilante over multiple episodes, and now we're expected to believe in his inner turmoil with only a few minutes to build it up. Felicity and Diggle have proven over and over again that they are willing and capable of being a part of Oliver's crusade, and it feels flimsy that an RPG and a spot of hallucinating would change Oliver's view of them so starkly.
Dr. Ray Palmer, introduced in the Queen Consolidated subplot, is another direct DC Comics reference. In the DC universe, Ray is the hero known as The Atom, an intelligent physicist and professor who develops technology that allows him to shrink to any size. Arrow's iteration of Ray Palmer seems to have him playing more of an Iron Man role, looking to take over Queen Consolidated and restore Starling City to glory. He also seems to have computer hacking skills similar to Felicity's preternatural abilities, breaking through firewalls at Queen Consolidated to snag the company's raw financial data for his presentation to the board. Ray keeps pestering Felicity to join him, going so far as to stalk her to the hospital where she is congratulating Diggle and Lyla on their new baby. Ray used the GPS on Felicity's cellphone to find her, and if he keeps that up I'm going to quickly sour on Dr. Palmer. I hope he doesn't, because a Roy-Felicity-Oliver love triangle seems inevitable.
Felicity, meanwhile, has shown remarkable loyalty to Oliver despite his sudden change of heart. Felicity is instrumental in his crusade to make Starling City a better place. She has walked into mob-run secret casinos and taken down Deathstroke, arguing that being a part of the danger of his crusade is her choice. She risks her job at TechVille, a thinly veiled reference to big box electronic stores complete with blue collared shirts and khaki pants, by hacking on the fly to help Oliver in a high speed chase. If Oliver drives her away and towards Ray Palmer, he's going to lose a lot more than he thinks he is gaining by ending their budding relationship.
In his fourth big fight of the episode, Oliver takes down the new Count Vertigo with a little help from Black Canary, while Felicity and Roy stop the Count's plan to blow up three more crime bosses by packing a bunch of C4 into a stadium. When last we saw Sara, it seemed like she was going to be away for a while, and soon the (plot) reason for her reappearance is revealed. After a sweet reunion with her sister Laurel on a rooftop, someone unseen but familiar to Sara arrives and puts three arrows in Sara's chest. The Black Canary falls, dead, on to the sidewalk where Laurel is walking, probably undoing much of what months of AA meetings has done to help get Laurel her life back. The murderer is likely someone from the League of Assassins, but we'll have to wait to find out who decided it was time for Sara to die. Ra's Al Ghul has been teased as the major villain for season three, but why would he decide to kill his daughter's lover now? Starling City has already suffered two terrorist attacks in two years. Could the League of Assassins have decided that it is time to wipe the slate clean, starting with the vigilante?
Bottom Line: "The Calm" isn't terribly calm at all, and seems to be trying to pack in as many complications to the beginning of the season as it possibly can. Arrow is at its best when its character arcs are given time to feel meaningful, and this season premiere is putting Oliver and his team through too much, too fast.
Recommendation: If this is the calm before the storm, I don't know if Arrow, the show or the vigilante, can weather what's coming.