Alphonse likes to dream when he's sleeping.
Sometimes (not often), he dreams when he's awake—he didn't used to, but that was Before. When he daydreams, it's not by choice, and it's no child's imaginary creation; it's always the same. A door, a stone door—no, it is larger than a door—a gate, maybe—inscribed with runes that seem to blur when he gets close enough to read them (as if he's seen the gate but can't remember the inscriptions) appears, and he doesn't want it to open. He is afraid it will open anyway.
It does, and he wakes up screaming and in Izumi-sensei's arms, breathless with terror.
The gate follows him everywhere. He hates it.
Sleep is different though, somehow. The gate is still there—but starting from inside himself, passing from one dream to the next, he is ready to face it. Inside himself, he knows it is just a memory in a way he cannot know when he's awake. In sleep, he is almost eager.
And somewhere between the darkness and the loss, in a place where Al can almost reach (one more alchemical bend, just a little further, just a little more), he can see his brother, waiting, grinning, beckoning.
Al wakes up peacefully every morning and smiles at the ceiling. Today, he tells himself: Today I will bring my brother back.
The gate is waiting, but Al is not looking until he has to.
Edward hates to dream when he's sleeping.
The Gate's chasing him down, it feels like; sometimes, Ed can see it out of the corner of his eye, but when he whips his head around to look, there's nothing there. Paranoia, of course—he can't make it come, nothing but death can—and sometimes a dark, calculating calm falls over him as he seriously considers strangling the nearest bystander. (It wouldn't take long, Ed could even snap his neck, and then drag the body with him as an offering to the waiting eyes and hands, and he sees them, wanting and wanting—)
When the moment passes, he sits cold from sweat, and his hand shakes so badly he must sit on it.
But the dreams hurt him in a special way reserved for the people closest to Ed, because they are bittersweet, sharp with fear and longing. Sometimes, he remembers, but mostly, he speculates (Al is dead, Al is alive, Al was reduced to a pathetic abomination like his mother)—how could the gate let Al pass through, when all Ed gave up was his arm and his leg? But still the Gate gapes open, every night, and admits Ed to its inky blackness, swallowing him whole.
Ed wakes up gasping for breath. This cannot go on, he tells himself; he has to return to Al, or he will really go crazy.
The Gate is waiting, but not for Ed.
The Gate is waiting for death.