Inspirations: The Girl Who Waited

Tom MacRae was a protégé of Russell T Davies, commissioned by him to write the story which reintroduced the Cybermen in 2006.

He almost came to write a second story for the 4th Series - a haunted house plot in which the Doctor encountered people making a Most Haunted style show (something which Supernatural did years before).

His second contribution finally comes here, when he came up with a timey-wimey storyline provisionally titled "The Visitors' Room". It later became "The Visiting Hour" and then "Kindness".

The final title was a nod back to young Amelia Pond in The Eleventh Hour.

The idea of Amy being trapped in an environment in which time ran at a different speed was there from the outset. Apparently the first 20 pages of script never changed between the first draft and the broadcast version.

One thing which did have to be taken into account was that this would Series 6's Doctor-lite episode. Matt Smith was off making Closing Time, spending only a day on the TARDIS set.

The way this is managed is rather poor - a disease that somehow only affects beings with two hearts.

Smith's unavailability at least allowed MacRae to concentrate on Amy and Rory, and it dropped some of the sci-fi elements and extraneous characters to concentrate on them - making it a bit of a romance.

As well as being the Doctor-lite story, it was also to be a cheap one. This is why we mostly have plain white rooms,  and location filming at the Cardiff Bay Millennium Centre - used many times before, most notably in New Earth.

The Handbots were originally envisaged as cloaked figures, with only their outstretched hands visible.

The "deadly touch" idea was inspired by Terror of the Vervoids, as Macrae recalled the Vervoids issuing toxic spines from their hands.

An early draft saw a hand chopped off a Handbot continue to move around by itself - inspired by Thing from The Addams Family. Moffat stored this image away for future use (see Flatline).

Unfortunately, Series 6 had already featured a well-intentioned medical artificial intelligence posing a threat - the Siren in the pirates story.

Thought was given to hiring an older actress to play the older Amy, but Karen Gillan fought to be allowed to play both roles. Neil Gorton had shown he could do effective aged make-up (such as Tennant sports in The Family of Blood and The Sound of Drums / Last of the Time Lords).

Facially, it's fine, but physically she doesn't really convince as an older woman.

Next time: The Horns of Nimon meets Crossroads...