It's the penultimate episode of Fox's Fringe, and now that we now the identity of Donald, perhaps it's time that even more revelations started to flow about the various mysteries of this season, no? Then again, maybe it's just time to raise more questions... Here are five from "The Boy Must Live"!

What Are The Observers Up To?

The comment from the Observers' commander - And I found myself liking the revelation that the man in charge of the invasion is, of course, nowhere near the front lines, but instead safely back in home territory, I must admit - that the Fringe team wasn't worth rearranging the timeline for interesting. Not because it highlights Windmark's current state (About which, more in a second), but because it highlights the strange rules of the Observers. Aren't they already rewriting the timeline by invading? Or is this all part of their plan… and have the actions of the resistance been part of that plan too, in that case? Is the plan "merely" to transform the Earth into a hospitable escape route from a destroyed future, or something else?

Are All Observers Destined To Have Emotions?

Windmark is, of course, going through an emotional awakening of his own, born of his obsession with the Fringe team; as if that wasn't clear from the scene with the commander, we then had his pause while listening to jazz, and his later calling Michael "the boy" instead of "the anomaly." Similarly, the Observer accompanying Windmark to September/Donald's apartment recognized something in the jazz as well, tapping his foot to the music (admittedly, almost entirely out of time, but hey; he's new at it). Should we take these hints to mean that the Observers haven't actually rid themselves of emotion, but just hidden it deeply - And if that's the case, will their new emotional reality be their downfall?

Why Wasn't The Plan Carried Out Earlier?

I'm somewhat confused, now that we know the plan, as to why Michael wasn't sent into the future earlier. If September/Donald and Walter were able to hide the boy in a pocket dimension, why couldn't they simply have sent him ahead in time then, especially as it appears that they had the tech all along? Was it because Walter wasn't ready to die yet? Why would that matter if, when the plan works, the timeline is rewritten to ensure that the invasion doesn't happen and therefore Walter won't be dead…? (Of course, then we get into the whole "If the plan undoes the invasion, then it'll mean that no-one will come up with the plan, so the invasion will happen" loop.)

Will Walter Die?

Next week is the final episode, and this season has brought a high number of casualties… If I were a betting man, I wouldn't be placing money on Walter Bishop's long-term survival. Especially if his sacrifice will being Etta back to Olivia and Peter.

Never Mind the Observers, What is Michael Up To?

Amusingly, just before the monorail scene at the end of the episode, I found myself thinking that no-one had actually checked with Michael about whether or not he was down with this grand scheme that would send him through time. Turns out, the writers were apparently thinking along similar lines, as he abandoned the Fringe team and turned himself in to the Observers. There's obviously some ulterior motive going on here, but what? Allowing the Fringe team to escape? Demonstrating his value to the Observers so that they send him forward in time? Could it be as simple as Michael changing sides altogether…?

Next week: The final episode, where all will be revealed. Or, perhaps, some will be revealed, and the rest will be politely ignored, judging by how this season has gone so far.