The gang were not unprepared.

McLean sprang to Nellie's back and raced after the Angel.

As they passed Duncan, he wheeled and followed.
Soon the pike was an irregular procession of barebacked riders, wildly driving flying horses toward the swamp.
The Boss rode neck-and-neck with the Angel.

He repeatedly commanded her to stop and fall out of line, until he remembered that he would need her to lead him to Freckles.

Then he gave up and rode beside her, for she was sending the bay at as sharp a pace as the other horses could keep and hold out.