How long did it take you to spot the Master hiding in plain sight? Or did the big reveal come as a complete surprise?

We knew John Simm's incarnation of the Doctor's Time Lord nemesis was due to resurface in this week's episode of Doctor Who, World Enough and Time, but we didn't know exactly when it would happen, or how.

History should have given us a clue, though – the Master is a, well, master of disguise, who has hidden behind a variety of prosthetics and monikers (usually with pretty direct references to his name) down the years.

And having still not announced himself a full 43 minutes into the episode, it felt as if time was running out.
That's of course if you hadn't already noticed that behind the straggly beard and hair, the fake nose, wrinkles, hunched posture and vaguely eastern European accent, new character Mr Razor was none other than Simm himself.

When he peeled off his face to reveal that trademark pinched pout and the new addition of a goatee beard – a tribute to past Masters – it certainly shocked his future self Missy, who clearly hadn't recognised her old visage underneath all that make-up.

It might have been a similar experience for viewers had the news of Simm's return not been leaked and then heavily trailed by the BBC – he would have been a lot less easy to spot if we hadn't been looking for him.

Nevertheless, knowing that it was coming only increased the tension and when it arrived it still felt like a big Doctor Who moment.

The question now is, what will the Master do for an encore? He is creating an army of Cybermen aboard a giant spaceship on the brink of a black hole, but to what end? And will the apparently repentant Missy be joining him in whatever evil scheme he has planned? She certainly looked pleased to see him after the initial shock wore off.

Doctor Who fans will no doubt feel the same.

Doctor Who series 10 concludes on BBC1 on Saturday 1st July