The client was Derace Kingsley. He had a voice you could have cracked a brazil nut on and a wife he'd not seen for a month.
He'd got a telegram that talked about a Mexico divorce and he wanted Marlowe to take it from there.
Marlowe found the guy she'd gone off with and he denied all knowledge. So it's off to the country cabins near San Bernadino where there's a dead lady underwater...