From publisher blurb:
Peacekeepers is a mini-setting for ICONS describing the world after an invasion of Ultimians. You could use it on your own or incorporate it in an existing campaign.
In this book you’ll find new threats and opportunities, some optional rules (like a Wealth system for Icons), a superheroic adventure generator and a random civilian events generator (to roll up what happens when you’re out of costume).
It contains an outline of a campaign, and two semi-related adventures, complete with a collection of unusual suspects.