Thats good, keep warm.

The first Doctors companions Ben and Polly appear briefly.

What is it good for?

Happy Christmas, gents!

He was very serious, and I had to be very serious too.

We started rather wild, and we mellowed as the time went on.

He once again worries about his web app history, as inThe Zygon InversionandSmile.

The first Doctor does wear his monocle, though, which he previously sported inThe Sensoritesback in 1964.

This was used during two stories in 1965:The Web PlanetandGalaxy 4.

The planet Villengard was mentioned in Steven Moffats very firstDoctor Whostory.

It appears the mutants have now developed a talent akin to a Facehugger from Ridley Scotts 1979 filmAlien.

Helens appearance is dated to 5,000,000,012, eleven years before New Earth and 41 years beforeGridlock.

As such, it is likely that Clay herself perished during these events.

She also appeared as Beth Halloran in theTorchwoodepisodeSleeper.

The Doctor references the rug Bill bought him as a Christmas present in her first episode,The Pilot.

A returning Nardole (hooray!)

tells the Doctor that if he dies, he believes everyone in the universe will go cold.

Nardoles adorable final line, cuddle, is a callback to the group hug at the end ofOxygen.

A similar line was cut from the 2007 tenth Doctor adaptation with the same name.

As inThe Doctor Falls, the TARDIS cloister bell rings out its ominous tones.

Its going to be interesting to see what if anything is left of the universe come 2018.

Well, folks, thats your lot!