"Well, goodbye, Doctor," Turlough said awkwardly, staring at the ground. "Like I said, Peri will take care of you now. I'm sure she'll do a good job."

The Doctor looked from Peri, to Turlough, back to Peri, back to Turlough. Then he grabbed Turlough by the arm, shoved Peri towards Malkon, and said, "Trade."

Before anyone could stop him, he dragged Turlough into the TARDIS and slammed the door. The next sound was that of the TARDIS dematerialising at top speed, and then came Peri's scream of protest as she realised she'd been abandoned in favour of the ginger lad.