I basically stumbled over the solution the first time through when I broke into Evelyn's house just to see if I someone would stop me, but I'd like to actually do it 'properly' - however, it seems I'm stuck. I got the mortician arrested and talked to all four suspects, but nobody had anything interesting to say and Evelyn just drained the stone and then didn't say any more. I dug up the body and talked to the dog, but so far I only managed to find something of Cecil's and Esmeralda for him to smell. I also found the Duke's love letter, but Esmeralda just brushed it off. Am I missing something here, is there more evidence to be found without just breaking into Evelyn's house?