This is what happened in Falling just after Cold as Ice.
Donnie couldn't sleep. Again. He did try, and it wasn't just the threat of Raph's nerve block; he knew that Leo needed him at his best. But eventually he was forced to admit that he wasn't getting back to sleep tonight, and if was going to be awake anyway, he may as well be awake in his lab making adjustments to the rift generator.
Which is the only reason he actually heard Michelangelo cry out in the dark.
Frowning, Donnie leaned in the doorway and looked in on his younger brother. He found Mikey awake as well, eyes wide, staring at Donnie.
"Mikey?" Donnie asked.
It was the only invitation Mikey needed. He was across the room in a heartbeat, slamming into Donnie and locking his arms around him. Donnie staggered, startled, his arms coming reflexively around Mikey.
Mikey's hugs annoyed him sometime. Especially when they came in the middle of a delicate experiment and resulted in the loss of several weeks of careful preparation. But this one was different. Donnie rubbed Mikey's shell until his breathing slowed. "What is it?"
Mikey looked up at him. "I dreamed Leo was in a fight." He smiled a little. "He won. I mean, it's Leo." A small tremor ran through him. "But it was scary. And cold."
Sighing, Donnie tightened his arms a little around their youngest. "Of course he won. You really think Leo's gonna let anything stop him getting back to us?"
"Nope," Mikey said against his chest. "But…we're gonna bring him back soon, right Donnie?"
Donnie nodded, his expression resolute. "Yeah, Mikey. Real soon." His face softening a little, he loosed his hold and patted Mikey's head. "You wanna come help me work on the machine?"
Mikey thought about it. "By 'help', you mean hang out in the lab and try not to break stuff while you do sciencey things?"
"Pretty much, yeah."
Mikey grinned. "Can do."
