From publisher blurb:
Sometimes you need to make a Fate Core supers game happen with no time to prepare.
This can be anxiety-inducing, but there’s no reason to fear lack of prep. Because, with the right tools, pickup games are a snap.
Empire City Adventures is just such a tool. It's actually an entire toolkit for running spur-of-the-moment superhero games using Fate Core and the Venture City Rules.