Donnie was used to things happening fast. A ninja lived or died by speed and the ability to react.

But this was just too fast, even for him, and he couldn't keep up with what's happening. They were working their way forward and then suddenly he was flying forward, and his vision blacked out, and he hit the floor -

It was freezing.

There was a pause, a second or two that felt much longer, before he tried to lever himself up with his arm and get out of the heap he'd landed in.

And failed.