Starts looking like this and ends up looking like that.
Wearing black robes of office, he retrieves the Doctor and the pc's, bringing them back to his quarters. As they enter, the Doctor becomes weak kneed and stumbles into the President, who shoves him away. Stepping behind his desk, the Lord President lets them know he was once known as the Master, and the Doctor's capture was just the first in a line of victories, culminating with control of Gallifrey and ultimately the universe!
"Not so fast, old friend," croaks the Doctor as he pulled himself to his full height and fixed the President with a steely glare, "you will never be my master!" A gun had suddenly appeared in his hand and he shot the Master, then turned to the pc's wondering if he should kill them. They point out that they rescued him, so he decides to not kill them right away, and shoots one of them in the leg.
Stumbling out of the room, they close the door and jam the lock as the ominous sound of a cloister bell begins warns the citizens of the capitol of imminent danger.
That is where I will leave it for now, I will be back later.