The Warrens are broke. Ruth Warren’s brother Harry Grey has just died. He owned a three-quarters share of a partnership on the Dead Lantern Ranch in Arizona, with Jep Snavely taking the other quarter. Since Kenneth Warren is consumptive and needs to move to a hot, dry climate anyway, they head to Arizona to live on the ranch. Because Harry was Snavely’s partner and Ruth was willed his share. Probate, what?
Yeah, so that’s not at all how that works. Ruth is not Snavely’s partner — Harry was. The ranch would have to be sold and the Warrens would take three-quarters of what it sold for.
We immediately learn several things about Snavely’s outlook on the world: people are bad, fences are bad, cattle are things that generate a bit of money but are otherwise of no consequence, and horses are great. Snavely just wants to be left alone on his 20,000 acre ranch so he can ride his horses in peace, and when Harry Grey was so unexpectedly killed in Mexico, he finally was. When the Warrens arrive demanding to live on the ranch, he asks Ruth if she’s shown the will to a lawyer and she bluffs that she has. So Snavely is aware of Ruth’s fundamental misunderstanding of the nature of what she’s inherited. Rather suggests he killed Harry and wants to keep the Warrens on the ranch so that he can kill them and thus keep living on the ranch.
And that’s exactly what the solution is. But if you just caught that in the first chapter, it was the only solution possible, never mind the whole rest of the book.