There’s been many ways for an ordinary person to step into the TARDIS and the world of a Time Lord.  More than 50 years ago, it was as easy as mistaking it for a police box. That happened a lot.  Sometimes it was by invitation. Sometimes it was by sneaking aboard.

This time, it was a crush, and a leap of faith.

SPOILERS BELOW

The addition of Pearl Mackie as Bill Potts was done beautifully in the season opener, which brings back Matt Lucas as Nardole as the comic relief and maybe more.  Bill is an ordinary girl who finds herself in a situation that’s anything but ordinary, and she is still curious. It’s almost a callback to the days of Rose Tyler.

It starts with Bill, who works at a university canteen (cafeteria), attending the Doctor’s lectures which literally discuss everything. One of his best lines is “the passage of time is an illusion, and life is the magician.”  She gets to his office and notices odd things like sonic screwdrivers in a coffee cup and photos of River Song and Susan Foreman (aka his grand-daughter). As they feeling each other out the Doctor agrees to be her tutor. Her foster mom isn’t sure about this.

Bill has a crush on a student named Heather (Stephanie Hyam) who has a star in her iris. She seems to be interested in a puddle that’s formed at the campus. Bill looks at it, too, and notices her reflection is odd. Bill notices the Doctor and Nardole are under the university, in front of what seems to be a vault. We’re not sure what’s inside, hopefully that will be investigated.

Anyway, Bill and the Doctor continue to meet as odd things continue to happen. Bill buys the Doc a rug for Christmas, and discovers it’s under his police box that supposedly is very heavy. Bill talks about how her mom died while Bill was a baby and that there aren’t many pictures. Suddenly, she finds more. Wonder how?

Heather looks at the puddle again and tells Bill to get closer. Suddenly, Heather disappears. The Doctor discovers the puddle is really shape-shifting oil from a spaceship and it has claimed the girl as its pilot. It also wants Bill as its passenger.

“Heather” follows Bill everywhere, and the Doctor has no choice but to show Bill his police box is anything but ordinary. Her response is odd, comparing the inside to a kitchen, then asking where’s the toilet. However, she sees what the TARDIS really is when they head to Australia, then to the other side of the universe 23 million years from now. She is stunned but takes it well. She’s shocked to learn “Heather” has followed them.

The next stop for them is unusual: the Daleks battling aliens in “Destiny of the Daleks”. “Heather” disguises itself as a Dalek, but her starred iris gives her away. Bill finally understands that “Heather” wants to be with Bill, to be her “passenger” because she remembers Bill wanting her not to go away. It breaks her heart, but Bill tells “Heather” to go.  Itt reaches out to Bill and they have quite the vision together, after which Bill is able to say goodbye. Nardole apologizes to Bill for the Doctor not noticing her tears. She suspects that wasn’t her tears from her eyes.

That’s quite an unforgettable experience, and out of concern the Doctor thinks she should forget it. Bill won’t hear of it, especially when she asks him what would he think if his mind was erased. With a musical cue that may remind people of Clara, and maybe a suspicion it may have happened to him, the Doctor tells Bill to leave.

Yet, a minute later, guess who Bill meets outside. It’s the Doctor, who says, “It’s a big universe, and maybe one day we’ll find her.”

So a new journey begins.

While it was mostly about the Doctor and Bill, Matt Lucas was very funny as Nardole, especially when he had to help when they were at the Dalek battle. He’ll make a great companion, too.

What’s next? According to the trailer, he’ll meet Missy again with her previous form played by John Simm. There’s Ice Warriors and retro Cybermen, and maybe we’ll know what’s behind that vault.