According to the TV episode To The Last Man, Harriet Derbyshire died a year after the photograph of her and the others was taken. That, according to the website, was in 1918, the same period that the episode was set. On the same website it mentions a posthumous degree awarded in 1920. That means that Harriet had to die in 1919.

Her death was always going to be one of the events of this story. In the end, it became slightly less central than I intended. The fight against the invisible creatures that came through the open rift was the main story.

Splitting Ianto and Alun and pairing them with Caldwell and Carter seemed a natural thing to do, and it seemed to work quite well. It allowed for two interconnecting stories to go on. It did mean that Lydia, Harriet and Quinn, with young Shaw faded into the background until the end.

I have a slight concern that the machine Ianto uses, inventory No. 1747, is slightly Deus Ex Machina. It is suddenly introduced in order to trace the invisible creatures while the artefact that caused the trouble, 1470, which seemed important in the first story turns out a bit of a red herring.

Harriet’s death was going to be a little more dramatic in my first idea. I was going to have her step in front of somebody else, possibly either Ianto or Alun, or even Carter. But then how often has that been done? It happened last night on The Doctor’s Daughter! It’s a bit of a corny plot device. Rather, I had her already injured having tackled one of the creatures, and hanging on just long enough to say goodbye to Carter, confirming that there WAS possibly, something between them.

CPR of the sort Ianto showed Quinn how to do was unknown until the late 1960s, when it began to replace other methods of artificial resuscitation. Ironically, a week after I wrote this story there was a news article in which it was said that cardio pulmonary massage without the respiratory part – the kiss of life – was just as effective. Kissing unconscious strangers has become less desirable since AIDS came along.