Last year, the New Lords of Time encountered the Robot Santas on Christmas Station. This year, Jack Harkness gets to contend with them. I think I will probably make this the last time they turn up. They are a little limited in their scope. But I thought they had to have one last outing.

A lot of my Torchwood Cardiff stories centre on Jack and his new found family relationships. The first story after Christmas heavily focuses on Grey. Some readers don’t like that. But Jack is by far the most interesting character in Torchwood, if not on TV generally. That is why BBC America have moved mountains to get John Barrowman to LA for Torchwood: Miracle Day. They know they can pack the series with as many big names in US TV as they like but without Jack there’s no show.

So it stands to reason my Christmas story features Jack heavily. And it starts with Jack getting blown to bits, so what’s new. The safety procedure Grey adopted at his command is one which would save him from harm if the tables were strongly fixed to the floor.

Living metal, capable of growth and self-repair, as well as replication is an idea that has kicked around science fiction for a while. The Doctor Who story Robot had an early example. The Replicators from some episodes of Stargate SG1 are another variation on the theme.

Martha doing the ‘autopsy’ on the first robot Santa owes a lot to the fact that there is an episode of CSI on TV virtually every day on some channel or another. The image of body parts laid out on a table is just imprinted on the imagination. What happened next was entirely my imagination, though I am sure it has occurred in science fiction or fantasy somewhere else before. Each disassembled part becoming a perfectly formed replica, big or small, of the original Santa is an example of fractals – patterns in nature that repeat themselves. It also plays on the myth we learn as children that if you chop a worm in half it becomes two separate worms.

Freezing the santas and putting them into an Iceland food warehouse until after Christmas was a simple solution I came to after rejecting several complicated ones, including flooding the lower levels of the Hub with a refined form of the metal destroying chemical used in the already mentioned Doctor Who episode, Robot. Of course, that IS what Jack intends to use when he gets around to it, but there is no need to go into details about it.

There is a question hanging in the air, though. WHO sent the Santas, and why? That might get dealt with in a future story – when I think of an interesting answer!