Sheila don't give up on Sprite yet, he was the active one, and should be fully aware of where his home is. Though if he can't get back in to his home tonight, it's very likely he will bed down somewhere for the night. I don't think I can give better advice than Doghouse135 , I would never have thought of doing that. It's OK to put Timmy in a small hamster cage for the night, just so you can leave the door open of their main aviary, excellent idea.
Fingers crossed for you and Sprite