This episode was inspired by an episode of the nature programme ‘Coast’ which focussed on the River Severn and the South Wales Coast. It began with the Severn Bore, showing how and why it happens. It went on to talk about some other natural wonders of South Wales, some of which also suggested plotlines, but finding a story that used the Severn Bore in some way was my first thought.

The next part of the story came when I was googling the River Severn to find out more about it and the Bore. I came across the name ‘Sabrina’ as the Latin for Severn and the goddess of the river and carried on exploring till I found the story of the maiden drowned in the river who became patroness of the drowned. The Severn is notorious for suicides, especially off the Severn Bridge. The most famous case in recent history is the possible suicide – never proven – of Manic Street Preachers guitarist, Ritchie Edwards. Fans reject it, but others claim he jumped from the bridge. The river estuary is very silty and bodies are easily lost in it, so nobody really knows how many people might have killed themselves that way. A sad, but true fact.

So the idea of the maiden, Sabrina, taking revenge on people who had murdered a girl and dumped her in the river came together. That brought me back to the Altolusso, the highest residential building in Cardiff. It is the building Jack stands on in the very first Torchwood TV episode. There, I have reconstructed what is something of an urban myth – the man drowned in a river in an apartment way above the river level, complete with dead fish that could only have come from the river. I don’t know when I first read a variation of that in a book of ‘unexplained’ incidents. Probably at school. There have been variations ever since. I think the X Files might have done something like it. But it is one of those ideas that can be retold.

The helicopter, of course, is a variation on the theme. And then, I had to think of an idea for the finale and went to find out what the highest mountain around Cardiff is. Obviously, I had noticed that there was a mountain nearby, but I didn’t know what it was called. It is, in fact, Garth Mountain. Or Garth Hill to the English.

Yes, Garth Mountain IS the one they based the Hugh Grant Film “The Englishman Who Went Up A Hill And Came Down A Mountain” on. But only very loosely, and Welsh people are justifiably cross about inaccuracies in that film, the unwanted influx of misinformed tourists who think they’re helping by putting more stones on the cairn at the top, and the patronising stereotypes of the film, which was in the same category as the pot noodle miner advert and Doctor Who’s Green Death for assuming that Welsh villages are full of people called Huw, Tom and other single syllable names who are known by their occupation not a surname.

The river pouring out of the victim’s mouth was slightly inspired by the undead Owen regurgitating his beer in a Day in The Life. That much is obvious. Of course, Jack couldn’t save him. He was never really meant to. Torchwood were meant to know what happened, file the report, and leave the whole thing as an unexplained mystery to everyone else, along with the ‘ghost’ of the river.