The Time Lords return in new Doctor Who finale trailer

We also see more of Sacha Dhawan's Master, who returned to the series right at the close of episode 9 – and it looks like his long-running feud with the Doctor is going to turn physical.

At one point, we see her forcefully push him – a rare act of violence from the clearly anguished Doctor, who looks like she might experience a stressful time of it in the finale.

And it may well be just as stressful for her companions; rumours persist that at least one of the group could leave the series. That said, the trailer merely shows a troubled looking Graham, Yaz and Ryan, with the latter taking up arms as he faces a troop of Cybermen.

Unsurprisingly, given the events of The Ascension of the Cybermen, we also see plenty of the iconic cyborg enemies, led by the Lone Cyberman – who first appeared in The Haunting of Villa Diodati.

Of course, considering the secretive nature of the finale, in reality the trailer gives little away. But it's sure to get fans talking as they look for answers to the Timeless Child mystery.

Doctor Who series 12 concludes on BBC One at 6:50pm on Sunday