12 issues of Harbinger were published through 1992. The Unity crossover was presented in issues 8 and 9. Shooter wrote issues 1 through 10. A Harbinger trade paperback titled "Children of the 8th Day" reprinted issues 1 through 4. This TPB also came bagged with a copy of issue 0 written by David Lapham.

When Solar recreated a world that became known as Valiant Universe, a number of super-powered beings emerged. The most notable of those w ere Harbingers, human beings with a wide range of psionic powers.

Throughout history, their powers tended to lie dormant, emerging in occasional bursts that were usually brought on by stress. That changed when Toyo Harada, a Japanese-born Harbinger, established the Harbinger Foundation. He hoped to study the Harbingers and the full extent of their powers.

He discovered that he was what he dubbed an Omega Harbinger, a Harbinger who possessed a full range of Harbinger potential. Harada decided to use his powers and resources to change the world for the better, no matter the cost. He began recruiting other Harbingers and creating programs to teach them how to better use their powers.

The most skilled recruits became Eggbreakers, Harada's elite enforcers charged with containing renegade Harbingers, among with other things.

In the early 1990s, Harbinger Foundation discovered the existence of Pete Stanchek, the only other Omega Harbinger that existed at the time. Harada hoped that he would become a valuable ally. However, Pete discovered the truth behind Harada's ultimate plan after his close friend, who was outspoken against the Harbinger Foundation and their methods, was murdered by Harada's assassins and an attempt was made to kill Pete Stanchek as well.

Stanchek fled the Foundation, taking his girlfriend with him, and decided to stop Harbinger Foundation from reaching its goals. To that end, they recruited other Harbingers. and continued to undermine Harada's plans in any way they could. [source]