What if the Doctor really had changed history, even just the tiniest bit?

1480: Leonardo da Vinci visits the stars.
1508: Vasco da Gama sets foot on Mars.
1585: Francis Drake begins charting the Asteroid Belt.
1588: Earth is destroyed by a storm of angels.

The Doctor was really enjoying his freedom. But now there's a Temporal Agent on his tail. Gloriana and the President of Gallifrey are not amused. And Susan's none too well either!

Possibilities, like the Doctor, have a habit of running away with themselves. But who cares, when the jewels are so dazzling...