When it's time to put Bridget back in the field, there is a large George-shaped obstacle standing at the gate, looking decidedly unwelcoming.
I open the gate half-way, but it's too scary for Bridget to venture in, as George is waiting to pounce on her. She stands and waits.
George and I have a discussion where I explain to him that he needs to keep the way clear for Bridget's re-entry. He moves off a few feet to one side and pouts, then crosses to the other side of the gate and pouts some more. He doesn't stay in one place long enough or far enough away for Bridget to risk coming in. She stands and waits.
Finally, for some reason (I like to think it's because he's actually trying to cooperate), George moves off further. Bridget says, "Aha, here's the moment" and scoots in through the opening. Quick off with her halter, and then it's George's turn to come out for a walk.
Bridget can read George a lot better than I can, so it's helpful that she can observe him too and take advantage of the right moment to dodge past him.