Parkinson's is bad enough, but can Mike handle the ravages of middle age? It's usually the little things you notice first - a little slower first step in the morning, forgetting an old colleague's name, that sort of thing. But Mike has been slapped with a major mid-life mortality blow: a notorious mobster named Norwood - aka Joey "the Lip" Balvino - has been living next door to the Henrys for 11 years.
The news that a career criminal was hiding in plain sight next door to a celebrated investigative journalist hits the newsroom and of course Susan can't resist rubbing Mike's nose in it, unleashing a barrage of bad gangster jokes and practical gags. Mike returns fire but privately wonders to Harris if he's lost a step professionally. Mike vows to get an exclusive interview with Norwood in jail. Harris is supportive but has his own secret dilemma: he's hooked up with Mike's sister Leigh. They both know Mike would be incensed to discover the affair, but the danger of being caught is just too much of a turn-on for them both.
Annie notices a change in Leigh: she seems downright happy. She must be seeing someone! Annie confronts Leigh, who plays coy but says there is someone and he just might be the one. Annie is now determined to find out who's putting a spring in Leigh's step. When Harris drops by the apartment with flowers, Annie tells Harris that Leigh says she may have found the one. Harris, an eternal playah, beats a hasty retreat and Annie's none the wiser.
Meanwhile Ian and Eve know that young Graham was friendly with next-door neighbor Norwood - and think their little brother might have a line on a reported large stash of cash that Norwood left behind. Graham reveals that Norwood did give him a valuable statue, but he claims he can't recall where it might be. The older siblings head off on a treasure hunt to the building dumpster only to discover Graham is hiding the statue - a cute owl. The three debate whether to break it open until Annie intercedes and announces she's confiscating the owl to give to the police.
Mike's prison interview with his old neighbor is revealing, but not in a good way. The mobster can't believe Mike never caught on to him and his crime family buddies. Reviewing the footage back at work, Susan once again mocks Mike, telling him he's done enough damage and she'll pick up the investigative story from here. Distraught, Mike heads into Harris' office for a heart-to-heart: maybe he should give up the investigative gig. But then the old instincts kick in and Mike starts noticing clues that Harris is seeing someone. Then Mike dramatically swings open Harris' closet door to reveal Leigh, waiting in yet another sexy disguise for her new beau. It turns out Mike's actually OK with the two of them seeing each other. As Mike leaves, Harris and Leigh realize that all the sneaking around is what made it so fun. Hmmm, it appears love's labors are lost.
Killing his rival with kindness, Mike proceeds to give Susan a tip about where Norwood stashed his money. Back at the apartment, Mike ties a bow around it all for Annie: he tells her he knew if he didn't give Harris and Leigh his blessing they might have gotten married to spite him. That leaves just the question of the owl statue. Could it be filled with diamonds or a secret treasure map? After getting an OK from Annie, Mike drops the owl statue after suffering an accidentally-on-purpose fumble (thanks, Parkinson's). But inside the rubble is simply a weathered sheet of paper with gibberish tips and the musings of an old mobster written for a child. Sometimes, secrets ain't all they're cracked up to be.