Fox’s Fringe finished its third season Friday night with a future excursion and causality loops out the yin-yang. But what do all these events mean for Fringe‘s fourth season?

WARNING: Major Fringe Spoilers Follow!

First, let’s examine the events in the Fringe finale that were left out of our spoiler-free review. As Peter finally enters the mysterious Machine, he instantly wakes up in Manhattan in 2026. reality-warping vortexes have begun to appear in the primary universe just as they did “over there”.

We soon discover that Peter’s actions 15 years ago resulted in the complete destruction of the alternate universe. Walter’s doppelganger crossed over before the final destruction in the hopes of making peace, and is now on the loose. Even more puzzling, Peter immediately assumes his future role (he’s aged along with everyone else) as a top Fringe Division operative and Olivia’s husband.

The deterioration of reality is being laid squarely at Walter’s feet. He’s been imprisoned again and is only released in a desperate attempt to stop a terrorist group from intentionally starting vortexes. It’s revealed that Walternate and the terrorist leader Moreau are working in concert. Walternate ambushes Olivia (Anna Torv) and murders her.

As Peter and Fringe Division deal with their grief, Walter (John Noble) comes up with a plan to retroactively save Olivia’s life. He tells Peter that he can’t travel directly to the past, but that he may be able to bring Peter’s consciousness into the future, essentially “cheating” the time-space continuum. Peter and Walter agree that there could be dire consequences.

Peter (or his mind, or something) flashes back to the present, where he’s still in the Machine. He uses it to somehow bring the residents of the alternate Liberty Island – Walternate, Fauxlivia, and Brandon Fayette (Ryan McDonald) – into the primary universe alongside their duplicates. Peter vanishes, and the Observers outside the Statue of Liberty state that the others don’t remember him, because Peter never existed.

Obviously there’s a ton of burning questions to sort through, most immediately how Fringe exists at all without Peter and the central conflict he provides. In and interview with executive producers Jeff Pinkner and J.H. Wyman, the pair revealed that both Walters and William Bell (Leonard Nimoy) still tried to cross over and succeeded, setting up the current war of the worlds.

As for Peter and star Joshua Jackson: he’ll be back. Says Wyman:

“He’s got a job. He’s still under contract. We can’t yet reveal what exactly we have in store for him, but he’s definitely not going out for other shows.”

Other questions asked of Pinkner and Wyman include: will Brad Dourif return? (No.) Will Emily Meade be back as Ella? (Maybe.) What happened in Detroit? (Not telling.) The two producers were tight-lipped when it came to plot details – but we’d expect nothing less from Abrams’ compatriots.

Obviously time travel will play a big role in Season 4. Walter stated in almost the same breath that he had sent the machine back in time and that he couldn’t simply go back himself, so expect Peter and Walter to be intimately involved with the creation of the Machine and the events of the First People.

As for the present, the recently united Fringe divisions will almost certainly be working together to somehow repair both universes. A possibility that crosses my mind is two or three-person time travelling teams, being sent back to specific points to try and “fix” reality. Expect a big episode in Detroit.

If Peter never existed, why did the Walters cross universes? Is Fauxlivia’s son still alive? How do the Observers fit into all this? How does the Machine work without Peter?  Where did he go?

For the answers to these questions, you ‘ll just have to wait until Fall 2011, when Fringe returns to Fox.

Follow Michael on Twitter: @MichaelCrider

Source: TV Line