An old cave, rumoured to be the resting place of a famed bandit called El Diablo, has suddenly begun to moan and no-one knows why. There by accident - Pete’s dad knows the ranch owners - the boys decide to investigate and came up against legends of the Old One, a scar-faced mystery man, two old prospectors and a gripping mystery. The first non-Arthur book (he gets the credit in every edition I've seen, William Arden (Dennis Lynds) actually wrote it), this is well-written, clever and full of atmosphere - well worth a read.
This is the cover in my beloved 1983 impression and it's interesting to see how the book is sold differently with the cover art.
