This is part of a series of reviews of Doctor Who in chronological timeline order.

Previous Story: Circular Time: Spring

It turns out, 30 minutes is all you need to tell an exceptional story. This is very cleverly and tightly written. David Warner is a fantastic Isaac Newton, you're really sold on his intelligence and the idea of deducing the future of Earth through the Doctor's coins was such a genius idea. The whole scene where he guesses exactly who the Doctor is as the Doctor gets more and more astounded was just great.

The Doctor himself is great in this story, he gets his chance to shine and be rather clever. I liked the cheeky reference to Jon Pertwee's Who is the Doctor? aswell. This story is full of witty remarks from both Newton and the Doctor and great if you enjoy hearing about the Doctor's other escapades. The Doctor and Newton share a touching scene at the end and a great way to wrap up this story.

Next Story: Renaissance of the Daleks