River Tam

Duo gasps himself into consciousness moments later, and then laboriously hauls himself up so he's leaning against the wall, instead of bearing half his weight on his wrist.

Which isn't looking or feeling so good. Duo yanks out his knife and cuts the zip tie. He gives a little gasp as circulation returns.

Then he turns (almost tipping over), and drags himself over to River's side, reaching up to cut her free as well.