These are brand, spanking new Season 11 cast members Tosin Cole, Bradley Walsh and Mandip Gill, who will be playing Ryan, Graham and Yasmin, respectively.
In the first of the three shots, which come to us courtesy of the Doctor Who Twitter page, Thirteen is working on some detail-oriented fiddly business involving what appears to be some kind of electronic device, as her new friends look on in concern.
There’s quite a golden glow coming from The Doctor’s work, and I think that might actually mean that she’s using her brand new sonic screwdriver, but we’ll have to wait for the episode to be sure on that point.