By Montykins
Holmes is still angry at Watson learning something about his past in the last episode. So instead of telling her about Irene, he gets really childish and petulant. Which, don't get me wrong, is a lot of fun to watch. So for most of the episode, the two of them are split up, which lets Holmes spend more time annoying the police.
And he has plenty of opportunity to do that as the case involves a family that's been murdered in exactly the same way as some people thirteen years ago. And the culprit, Wade Crewes, was brought to justice by Captain Gregson, who doesn't take kindly to the suggestion that maybe he got the wrong guy back then. He's also quite put out by the revelation that the arrest came on evidence that was planted by his partner. To be fair, though, the guy does sound like someone who'd kill a bunch of people.
While Holmes is pursuing this investigation, Watson is off at the rehab facility that Holmes recently left. None of the doctors learned anything about Holmes, but the amiable gardener is also a beekeeper. Naturally. So she manages to get some letters that Irene sent Holmes. She doesn't read them, so Holmes likes her again. Although he does stick the letters in a blender, so he's still at least a little petulant.
The murder case briefly leads Holmes and Watson to a one-eyed fan of Chechen football, but that's quickly dismissed as a red herring. The actual deal is that Wade Crewes had an illegitimate son who volunteered at the prison, taught him to read, and then went out to duplicate his father's killings in hopes of getting him freed from jail. It doesn't work.
And then Holmes tells Watson that Irene died.