Just Who is Neil Patrick Harris playing this time?

Neil Patrick Harris, American star of stage and screen, has joined the cast of Doctor Who and is currently filming scenes set to air in 2023 as part of the show’s 60th anniversary.
“It’s my huge honor to open our studio doors for the mighty Neil Patrick Harris… but who, why, what is he playing?” said showrunner Russell T Davies. “You’ll just have to wait. But I promise you, the stuff we’re shooting now is off the scale. Doctor beware!”
Harris joins David Tennant, Catherine Tate, Yasmin Finney and Who-knows who else in the Doctor Who 60th anniversary special next year …