This is set when Ed and Al are still training with their teacher Isumi.
Alphonse
Ed awoke to the sound of thumping. He turned over on his side and saw Al jumping up and down. "Al? What time is it?"
"It's midnight Nii-san."
"What's with the jumping?"
"I went down for a glass of water. Well, I was half asleepso Ipoured myself a huge glass of sugar instead."
"You idiot." Ed gets out of bed and walks down the hall with Al, jumping, following him. Ed goes into the bathroom and Al continues jumping outside the door. Then Ed goes back to the bedroom, Al still follows him while jumping. When Ed gets into the bed Al jumps beside it. He just happened to pick a squeaky board to jump on.
"Ed?"
"Yes?"
"You okay?"
"Yes."
"You sleepy?"
"Yes."
"Need anything?"
"No."
"How 'bout now?"
"No. Can you stop jumping?"
"No, I've already tried."
"Try again."
"Need anything?"
"Yeah, water." 'With him bouncing down the stairs it will be enough time for me to be fast asleep before he comes back.'
"Be back soon!" and he goes bouncing out the door. Two minutes later Ed isalmost asleep and Al is at the top of the stairs. Isumi catches him before he jumps down the first step. "You've been into the sugar I see."
"Sensei! Not on pur-"
"You know your not supposed to do that!"
We bring our story to a close on the scene of Al getting Isumi's idea of divine punishment, and Ed listining to the chase with a smile on his face. Let us say that Al never got a glass of water at night anymore, he made Ed do it.