After the Spy Master unveils his CyberMasters to the Doctor, he proceeds to test them out by having one zap the other. The Master laughs as the shot CyberMaster regenerates, before immediately running away when a Dalek emerges from said regeneration and zaps the other CyberMaster. The Doctor explains: "That's the problem with regeneration. You never quite know what you're going to get!"
- The Doctor says "you never quite know what you're going to get" with regeneration.