I'm pleased to report that both novels are now doing well after yesterday's operation to separate them. For a while it looked as though the mainstream novel might not survive, but it made a miraculous recovery overnight and is now off life-support. Last time I looked in on it, I discovered that it is busy growing a new love interest and has decided that it wants to be set in a stately home open to the public. (This is clever of it because it will suitably explain the coke-fired central heating, which is integral to the plot but which I suspect is vanishingly rare these days.) Also *light bulb moment* these novel fragments may well fit with some ideas I have hanging around relating to murder mystery weekends.
The fantasy novel is looking good too. It doesn't actually need more beginning, it just needs the severed ends stitching together with perhaps a small skin graft to hide the join. It does, however, need a new title. The mainstream gets to keep the current one.
There was a moment of difficulty when both protags wanted to keep Carlo, the little Yorkshire terrier, but he has to stay in the fantasy novel because the idea of a Yorkie in Faerie is just too cute to lose. :)