The Doctor feared the worst when the other Time Lord froze in his arms, suddenly remembering that only a few moments ago they'd been fighting tooth and nail. Not best form really, hugging someone who was probably still mad at you. But...

When the Master's arms came up around him, he blinked a little in surprise before sighing in relief, a bemused smile on his face.

"It's been ages since I've laughed like that," he said eventually, a small smile still in place.