Doctor Who 10x1 -

Bill is drawn to the Doctor’s lectures and he eventually agrees to tutor her.

It was designed as an entry point for new viewers, explaining the TARDIS and the Doctor’s nature through Bill's inquisitive eyes. Doctor Who 10x1

The story follows Bill Potts, a canteen worker at St. Luke's University, where the Doctor has spent decades posing as a professor while guarding a mysterious vault. Bill is drawn to the Doctor’s lectures and

The fluid mimics Heather and pursues Bill and the Doctor across time and space—including a brief encounter with a Dalek battle—to find a "pilot". Doctor Who 10x1

Bill becomes fascinated by a girl named Heather, who has a distinctive "star in her eye." They find a puddle that doesn't reflect correctly; it is actually a sentient fluid from an alien ship.