When you watch Doctor Who Season 10 Episode 1 online, the Doctor has been for decades serving as a professor at a university in Bristol, aided by the faithful Nardole. No one knows what exactly he's a professor of, but everyone attends his lectures, even when the content isn't what was on the course material. A young woman, Bill, is bright and curious, and sneaks into his lectures. After he notices, he offers to be her personal tutor. So when Bill runs across an odd puddle and a friend mysteriously vanishes, the Doctor takes a keen interest, especially when he realizes that the puddle of water isn't a puddle of water at all, and their reflections aren't reflections. And, boy, is Bill shocked to discover the truth about the eccentric man who's been tutoring her! It's up to the Doctor, Bill, and Nardole to discover what happened to Heather, why she seems to be pursuing Bill, and if this has anything to do with a mysterious locked vault underneath the university. The adventure will lead the three heroes from Bristol to Australia to the other end of the universe, and back again. Find out what happens when you watch Doctor Who Season 10 Episode 1 online.