With the Doctor (played by Peter Capaldi) now blind after he failed to repair his eyesight, it seems that he is getting some help from old friends.
As he feels his way along the mysterious vault, the short tease is immediately followed by a tantalising glimpse of old “frenemy” Missy (Michelle Gomez).
Although it is not strictly confirmed, continuity suggests that Missy is actually inside the chamber as her image follows that of the vault.
This would align with what many fans believe is the true theory behind this season’s big mystery.
Regardless of what her return means for the Doctor and his new companion Bill Potts (Pearl Mackie), fans have taken to Twitter to air their delight at her debut in season 10.
One wrote: “I forgot to mention how impeccable this week’s episode of Doctor Who was, it was so thrilling. I can’t wait for next week and MISSY IS BACK.”
Another posted: “What’s going on??? The Doctor is blind… And Missy! #DoctorWho #TimeForHeroes.”
A third added: “Ooo exciting to see Missy back! #DoctorWho.”
Doctor Who continues Saturday on BBC One at 7.25pm.