With recent episodes focusing almost exclusively on the war between the two universes, I almost completely forgot about the existence of Olivia Dunham's estranged evil stepfather. It's a good thing the folks at Fringe haven't. TV Line reports that Olivia's abusive stepfather will finally make his first appearance on Fringe later this season, though the role has yet to be filled by an actor.
For those who don't remember Olivia's stories of her stepfather, Fringe Wiki has an excellent breakdown of our hero's abused childhood:
Olivia's stepfather, an abusive alcoholic, would beat Olivia's mother while accusing her of adultery. Olivia's mother remained silent about this to everyone else. On one occasion, Olivia's stepfather broke her mother's nose before leaving the house and driving away. Upon his return, Olivia shot him twice with a handgun. The wounds were not fatal, a fact that Olivia regretted for the rest of her life. After recovering from his wounds, her father left for an unknown location. Since that day, Olivia's father has sent her a greeting card every year on her birthday, to taunt her and remind her that he is still alive.
The character was first mentioned in episode six of season one, "The Cure," but has had little to no direct impact on the storyline since then — as far as we know, that is. It's entirely possible that Olivia's stepfather has been pulling some behind-the-scenes strings for the past three seasons, but I'm hoping his involvement is a little bit simpler than that: this is one of the few average men, powerless as far as we know, that truly terrifies Olivia Dunham. Given the recent flood of alternate universe and world-threatening storytelling — all of which has been fantastic, mind you — seeing Olivia's dreaded stepfather in a fairly grounded light would be a nice change of pace for the series.
That said, I wouldn't be too surprised if the two Olivias find common ground through their evil stepfather. There have been differences in their upbringings, of course, but this could be an interesting bonding point for the two parallel adversaries, don't you think?