Well, there went the uncertainty. Suddenly, the Master had pushed him against the wall and was pressing his mouth against his, harshly. The Doctor struggled against the wall, struggling to push the Master back, then turn him against the wall as he returned the kiss fiercely.

This was something the Valeyard would've loved. The dead at their feet, the struggle in this---whatever it was---it was something he wanted. He couldn't have it. Maybe that was why the Master wanted it. It was something he could keep from the Valeyard.

The Doctor approved.