DC Comics online (not free but only .99 cents). Click links for more details, but here's THR's description
of the series...
"To gear up for the launch of the fourth season of Fringe, a digital comic series by DC Entertainment written with series star Josh Jackson has debuted.
Beyond the Fringe, featuring cover art by Drew Johnson, will explore pivotal events that take place between the third and fourth seasons of the Fox sci-fi drama, and will also look at alternative scenarios."