Knockdown

Jonah Dereham used to ride professionally; now he buys and sells horses for other people instead, working the bloodstock trade rather than the track. He's at auction on commission from a wealthy American client, bidding on a horse worth having, when the actual subject of the book shows up: a gang of horse dealers who don't like losing that bid.

What follows isn't really a mystery so much as a siege. Dereham takes a blow to the skull right after the auction, and it doesn't stop there — one attack leads to another as he keeps refusing to back off a deal the gang wants for itself, and what starts as bad blood over one horse widens into a horse-trading racket with a murder in it. Francis rode as a jockey himself before he wrote, and it shows in how exactly the book handles the bloodstock trade — how a horse actually gets bought, sold, and swindled at auction — which is the real crime underneath the violence, not decoration around it.

It's a stand-alone, not part of a series, and it runs on the pattern most of Francis's non-series books do: a straight, competent professional targeted for doing his job correctly, who absorbs real damage before it's over. The reservation is that pattern itself — read enough Francis and the shape stops surprising you — but the bloodstock racket and the American client's horse at the center of this one are specific to it, not recycled from somewhere else across his forty-odd books.