I think it's Brenda Clough in rasfc who uses the metaphor of a boa constrictor for a story in the early stages. She reckons that if you can pin down its head and its tail, it then becomes easy to gradually wrestle the rest into submission. Well, that isn't quite my problem. I know how it starts and I know how it ends and I have at least a vague idea of what happens in between, but I haven't yet managed to make any progress with actually writing the thing.
Revealing Secrets was supposed to be funny. A light-hearted romp through the British Further Education system, that's what I'd planned. But it's demanding Lyrical Passages also Dark and Genuinely Scary Bits. I think this might be why it's sulking and refusing to progress. There's a tussle of wills going on here. Eventually the story will win, but until I get the overall tone right, I can't do anything with the beginning.