From the introduction: Darkness and Light is a character sourcebook for Vigilance, SuperHero d20. Inside you will find Villains, Heroes, and those in between. Some Villains found here may yet be claimed from the darkness and brought back into the light by the intrepid hero. Included with each character are adventure hooks, along with general advice for using the characters in your campaign. Many of these characters have relationships with each other, further allowing the GM to build whole campaigns around the adventure hooks, with one character leading the players to others.