Half-Face Man

The  was a Clockwork Droid assigned to the SS Marie Antoinette sometime in the 51st century with the mission of finding a fabled realm of paradise. At one point, the ship crashed on Earth in prehistoric times and remained stuck on the planet for millions of years. For eons afterward, lacking the proper technology to keep itself pristine, it stole replacement parts from the environment around it, some of which were taken forcefully from living creatures.

Eventually, it had added such a large mixture of biological parts into itself with its machine components that its appearance was half-man, half-machine. Consequently, it gained vestiges of emotion and personality, letting it recognise that it was committing murder and working towards fulfilling an empty goal.

Early life
The Half-Face Man was originally the control node aboard the time-travelling ship SS Marie Antoinette, sister ship of the SS Madame de Pompadour. At one point, the ship crashed on Earth in the planet's distant past. With the ship damaged, the clockwork droids aboard the ship remained stuck on the planet for millions of years, replacing their parts using both organic and mechanical parts. They did this time and time again as they got older, until there was virtually nothing left of their original selves at all. (TV: Deep Breath)

Harvesting organs
By Victorian times, the Half-Face Man had begun harvesting organs from humans in the city of London. This included the eyes from a man named Alf and the hands from two separate humans. The droids incinerated their targets to conceal what had been taken from them, ensuring their presence in London was invisible. The Half-Face Man at one point also acquired Mancini's Family Restaurant and turned it into an organ-harvesting factory, whereby guests unlucky enough to enter it would be taken down below into the droids' crashed spaceship and their organs used to repair the ship.

When a dinosaur mysteriously appeared in the Thames, the Half-Face Man extracted tissue from its optic nerve to use as part of his ship. He then incinerated the creature so as to leave no trace of his presence. This did, however, alert the Doctor, newly regenerated into his twelfth incarnation, to their nefarious activities throughout London.

The Doctor and his companion, Clara, were led to the restaurant by a mysterious coded message left in a newspaper. They were then taken down to the spaceship and accosted by the Half-Face Man, who revealed to them that his sole objective was to reach the "Promised Land". While Clara and the Paternoster Gang fought the clockwork droids, the Half-Face Man escaped to the ship's escape capsule, a hot air balloon made of human skin. There, the Doctor managed to convince the droid that the Promised Land did not exist, and so the robot either fell — or was pushed — to his death on top of Big Ben. His death deactivated the rest of the clockwork droids, saving the Doctor's companions. (TV: Deep Breath)

The Promised Land
The Half-Face Man's mind was uploaded to the Nethersphere. (TV: Dark Water) He found himself in some sort of garden, where explained to him that he had reached the "Promised Land" — he was now in Heaven, at last. (TV: Deep Breath) The Nethersphere ultimately perished, however, following the exposure of the 3W Institute and the destruction of Missy's Cyberman army by Danny Pink. (TV: Death in Heaven)

Abilities
The Half-Face Man was equipped with a blowtorch hidden underneath one of his human hands. He used this both as a torture device and to look threatening as well as, presumably, to incinerate his victims so as to remain undiscovered. While he was immensely clever in some capacities, his programming was also rather limited in other respects, and was, like his fellow clockwork droids, fooled into thinking an organic was a droid like him as long as they were not breathing. (TV: Deep Breath)

Behind the scenes
The Half-Face Man was played by Peter Ferdinando and was thought up by Steven Moffat. "I wanted something really quite simple for the new Doctor to battle, because it's not really about the menace," stated Moffat, "and I wanted there to be some sort of echo; as a newly regenerated Doctor, he's meeting a man who's constantly rebuilding himself and can't really remember why. There's stuff to play with there. You want an opportunity to be creepy, and exciting, and fun, without having to get into too much of a worry about what the monsters are actually planning." (Doctor Who Magazine, issue 477, p. 19)

In the stage directions from the script for Deep Breath, the Half-Face Man was initially described thus: "Tall, thin [....] An impossible thing [....] The man's head is only half there. One half is a normal face, torn raggedly down the centre. The other half is a lattice-work of steel and bone and wire — you can see directly through it, like a bird cage — and there appears to be a real eye, mounted in this grotesque structure [....] The voice [...] is rusty, rumbling, almost mechanical." The script also referred to the Half-Face Man as having "Frankenstein style stitch marks round the wrists."

CGI was used to give the impression that the Half-Face Man was missing much of the right side of his face. Noted Steven Moffat, "We didn't wimp out and have him put a special covering on it to save on CGI." (Doctor Who Magazine, issue 477, p. 19)

Moffat was pleased with how the Half-Face Man turned out. "To see through somebody's head while they're talking to you seems utterly creepy to me," he commented. "The finished effect is amazing. You can see through the half of his face! It's quite something. You can see things moving behind him [....] Every time he's in shot, you're seeing through half of his head, which is just... creepy." (Doctor Who Magazine, issue 477, p. 19)

When asked what ultimately happened to the Half-Face Man after Missy uploaded his consciousness to the Nethersphere, Moffat speculated, "Well, either he became a Cyberman, or she [threw] him away as being a bit too rubbish. I suspect the latter." (Doctor Who Magazine, issue 481, p. 6)