From publisher blurb:
Warlocks treat not only with the maddening fey or strange, outré powers from the void, but with astral creatures of light and strength. Known to mortals as angels, most assume these creatures are messengers and servants of benevolent deities. Some warlocks have discovered the ancient thaumaturgies and rituals used to invoke the creatures that roam the Astral Sea. These warlocks can channel life-giving power, or blast their enemies with searing light and the awesome might of the heavens.
This pact features a full listing of powers from Levels 1 through 30, two new Feats exclusive to the pact, a paragon path, and three new magic items.