AU. In 1938, Albus Dumbledore heads to a London orphanage to deliver a letter to a muggleborn student, and decides to be reasonable when encountering Tommy Riddle.

Petunia married a biochemist, and Harry grew up reading science and science fiction. Then came the Hogwarts letter, and a world of intriguing new possibilities to exploit. And new friends, like Hermione Granger, and Professor McGonagall, and Professor Quirrell... COMPLETE.

In one world, the war against Lord Voldemort is raging. In another, a Hogwarts professor named Tom Riddle decides to put his theory on alternate worlds to test and embarks on a trip that quickly turns into a disaster. AU sixth year. DH compliant.