It's dark.
When you don't know where you are or how you've come to be there, even the simplest things can be supremely frightening.
So it was that when Walter awoke, his consciousness confused and hazy, the thing that he fixated on was the darkness. A darkness so thick and oppressive that it could've been a blanket - perhaps it was, for all that the disoriented boy knew. A quick rustle around his immediate area made it clear that no, he was not bound or covered by anything in particular - it was just... dark.
He'd been awake for a few minutes, and his eyes hadn't yet adjusted, as they normally would. In the back of his mind, Walter rationalized that this must mean that wherever he was had a true and complete absence of light - there was nothing for his eyes to adjust to, so waiting around in the hopes that he'd suddenly be able to see where he was going was a rather pointless endeavour.
He rose to his feet unsteadily, and reached out to grasp at - what? A wall? Anything, anything that might've been there to help him launch off of the ground. Nothing met his fingertips, and after an embarassing moment of swaying, Walter tentatively took a few steps forward. He didn't run into anything, so he continued walking, slowly, and with one hand out to his front, and one to his side - just in case.
Hours passed as he walked. Or at least, he assumed that they did - total darkness, with no exposure to the grounding reference of the sun or moon, made it a bit difficult to figure out exactly how long he'd been in this... place. But Walter knew that logically, if he only kept walking, he would eventually end up... somewhere. Even if it was a dead end, at least it would be reassuring to have found something concrete in this strange place.
Eventually, he is tired. He must have been walking all day - or night? Well, whichever; either way it's been a long time. He plops down on the ground, falling a bit too quickly, and yelps a bit at the impact. It's then that he realizes that he hadn't tried to speak or call out at all until now - this was the first noise he'd made. How silly of him - what if there was someone else around, someone else lost in the darkness that could help him? Cautiously, Walter tests out his voice, calls out and asks, "Hello?" He is surprised by two things - first, that his voice was already so rusty and throaty from just one day of solitude, and secondly, and more importantly, that the sound of his voice does not carry at all. It's instantly swallowed up by the same damned darkness that's been surrounding him since he first woke. This realization sends a chill down his spine, and he tries to distract himself by talking himself into an attempt at sleep. After some hours spent laying there, in the too-quiet darkness, he finally succumbs to a deep, dreamless sleep.
Waking up in the black is just as disorienting the second time; and that's not all the stays the same on Walter's second day in the... well, wherever he is. He walks just as long as he did the day before, only stopping when his body can go no further. He shouts a few times, but eventually gives it up as his voice is instantly absorbed and he decides that his energy should be saved for his journey, rather than needless yelling.
This goes on for awhile.
Days cycle into months; months into years. Or so Walter thinks. He doesn't really know, after all. In fact, he's made the decision to delude himself into believing that his perception of time is so messed up that it's really only been a few days - he tells himself this to quiet the sick feeling deep in his stomach that grows stronger with every step.
Finally, he gives up. He stops walking and sits, then collapses backward onto the floor, staring up at what should be a sky or ceiling but in reality is just more darkness.
Eventually, his breathing stops, and the quiet, dark world he found himself in is truly silent once again, without even the sound of Walter's heartbeat for the blackness to absorb.
And that is the end of Walter's story.
