Anyway, Olivia points out it was twenty years ago and Walter reminds her that it's not for the kid. "Like Cecil, to him, he's only been waiting for days," says Walter and Peter looks over at sad Cecil, who's too bummed out to tell Walter not to talk about him like he's not even there. But Walter figures they used this place to hide the kid, to keep him safe until someone could return for him and he tells Peter to press play on the tape and show him more.
On the tape, Video Walter is pointing out symbols on the doors, which -- amusingly -- are the commercial-break glyphs: the six-fingered hand, the Fibonacci seahorse, the embryo apple, which is what they're looking for. Current Walter murmurs that the markings are very strange. Quick! Which way are they facing? Where's the yellow dot??
In the video, Walter finds Room Embryo Apple and jovially tells Lil' Baldy to wait. Our Fringe heroes have found Room Embryo Apple too, and -- just as in the video -- the key is on top of the door frame. Walter opens it, steps inside and... nothing.
It's an empty room. It's a very tidy room -- the bed is made -- but there's no one inside.
On the video, Walter explains to the kid that they designed this room just for him, and he must stay there and wait for them to return for him, adding that for them it could be quite a long time, but for him it will seem like no time at all has passed. In the background, we can see Donald -- the back of him, anyway -- placing a couple of objects on the bed. (He has hair, which on the surface rules out September, but it's entirely possible that September be-toupeed himself as a disguise? At any rate, they leave the kid there with a little bag of M&Ms -- aw, the M&Ms! -- and a coloring book.
Outside the room, Video Walter quietly tells the video camera that how they've seen where they've kept him. "To understand his purpose, refer to Tape 8." Oh, there's always one more tape!
Olivia suggests that Donald has moved the kid -- after all, it has been twenty years. Meanwhile, Peter is examining a large machine in the room that he thinks is a portable air-degradation unit. Man, that thing must use a lot of batteries! The air-degradation unit makes Olivia think the kid is an Observer, but an angry Walter snaps that it doesn't make a difference: "He was part of the plan somehow. And without all of the parts, the plan is useless!" He's yelling by the end, and Olivia tries to calm him down, but Walter's not having it: "No, it's too late! They must have gotten this out of my mind! Windmark. He must have found the boy! Everything we've done is for nothing!" He's red-faced and shaking by this point, and he stomps out of the room.