10 Most Confusing Scenes In Doctor Who History

10. The Paradox Machine

Let's not get started on how the Tenth Doctor is de-aged by good vibes – the most confusing thing about Last of the Time Lords is the Paradox Machine.

Specifically, it's why exactly the Doctor waits so long to let Captain Jack pump several rounds into it with an assault rifle.

When they first discover the Paradox Machine, the Doctor is keen to point out that he can't stop it until he knows what it's for, and that if he touches the wrong bit, it could blow up the solar system.

This implies the machine must be carefully de-programmed, like cutting the correct wire in a live bomb – but then Captain Jack comes along in the very next episode and wildly rains down metal hell upon the machine like he's playing Call of Duty.

Even more confusing is that the Doctor knows the Paradox Machine will kick in at 8:02, two minutes after first contact with the Toclafane. So why not just hang out in the TARDIS for a bit and destroy it then?

You could've saved yourself all that time spent as a house elf, and saved Martha's family from a terrible ordeal. Come on Doctor, you're smarter than this.