Personally, I had no doubt that Capaldi would be making an appearance in the first episode of the new Doctor Who spin-off, considering this synopsis recently released by the BBC:

Time has looked at your faces now. And time never forgets…
What if your planet was massacred and you were the sole survivor?
What if a legendary figure out of space and time found you a place to hide?
But what if the things that want to kill you have tracked you down?
And worst of all, what if you haven’t studied for your A-Levels…?

Like all sixth formers, these four Coal Hill School students have hidden secrets and desires. They are facing their own worst fears, navigating a life of friends, parents, school work, sex, sorrow - and possibly the end of existence.

Coal Hill School has been a part of the Doctor Who Universe since the very first episode, but that has come at a price. All the time-travelling over the years has caused the very walls of space and time to become thin. There’s something pressing in on the other side, something waiting for its chance to kill everyone and everything, to bring us all into Shadow.

Fear is coming, tragedy is coming, war is coming. Prepare yourselves, Class is coming.

Filming just started, but right off the bat, several fans in Cardiff have already tweeted pictures of the TARDIS parked prominently on a street corner, a letter to local residents explaining what they’re filming, and the following image revealing that one of the buildings of Coal Hill Academy is named after a former companion. (Though I’m a little disappointed it isn’t called the Barbara Chesterton building. You know she and Ian would have gotten hitched and started making babies the moment they made it back to London.)

one other interesting note: Paul Mark Davis has been contracted for a “reoccurring” role on the new series. While he’s played several different characters on both Doctor Who and The Sarah Jane Adventures, he’s best known for playing Sarah Jane’s primary nemesis, The Trickster, and considering that character was largely abandoned following Liz Sladen’s untimely death, it wouldn’t be a huge leap of faith to assume the character is coming back to menace a new batch of kids. Or maybe they just know he can do creepy and doesn’t mind prosthetics, and this time he’s going to be playing Omega.