Below are light to mild ARROW spoilers.
Arrow opens to what appears to be an idyllic setting where Oliver and Felicity are living the perfect life in the suburbs. Yikes, it was almost too perfect. Of course.
But Oliver's old team Laurel (Black Canary), Diggle (Diggle Man), & Thea (Speedy) have been facing off with a new nemesis being called the Ghosts. They strike, stealing hi-tech gear.
Later, their boss, Damien Darhk (Neal McDonough) makes a brazen appearance with the acting city council of a sort telling them they will all be dead, like most citizens of the city, so they can rebuild the city from scratch.