Dr. Nefario: [a minion drinks from a bottle, starts floating] We've been working on this for a while now. It's an Anti-gravity serum.
[the minion floats out an open skylight]
Dr. Nefario: I meant to close that. He'll be alright, I'm sure.
Gru: Do the effects wear off?
Dr. Nefario: [looking up at some minions floating on the roof] Uh... so far, no. No, they don't.