All three Camden generations dread the annual visit of Eric's parents, "The Colonel" (John Camden) and Grandma Ruth Camden. The tension between father and son is heightened when both Eric and "The Colonel" want to adopt a homeless and orphaned nine-year-old boy, George. Annie discovers the fate of her lost wedding rings when seeing them on a woman at the store.

A visit from Eric's parents, strict Marines colonel John and his equally military wife, strikes controlled terror among the grandkids, and even Jimmy Moon, who initially discarded Matt's accurate imitation of the usual boyfriend-grilling. They come to present George, the charming, manly boy they adopted from an orphanage. But Eric discovers detective Will Grayson, whose death was faked in a witness protection program, is back in Glenoak after the crime king's death in prison. He claims his son, none other than George, back, as remains his legal right. After a fugue attempt from George, a creative compromise is devised. Matt meanwhile discovers aunt Julie is on the verge of an alcohol relapse.

Matt worries now he's about to leave home, as self-absorbed, phone-glued Mary hasn't even got a clue what's happening with their younger siblings, nor is any use for either. Simon is heart-broken when Happy's original family head Jack Martin turns up and returns with a lawyer to claim the dog back. Eric considers his parents's surprise visit awkward and pointless as Matt won't be around to hold his valedictorian speech. The colonel however takes charge of an operation dog rescue inspired by Jimmy and Rod. Those two also undo Lucy's idiotic dumping of Kenny for being 'too perfect to be interested in her' and hold a remarkable church sermon. Matt changes his plans after a call from the colonel, learning about it and Annie's confession that Mary's pregnancy diagnosis got mixed up with her real one.

Mary and Lucy selfishly make Matt feel 'guilty' he hasn't moved out yet, although Annie still hopes to keep him home in a garage apartment. They even get Hank to find him a menial morning job in the hospital cafeteria. But Simon feels desert when Matt takes an apartment with John Hamilton. Eric and Annie worry about the Colonel's attitude to Julie's marriage, but the grandparents have gone soft after an around-the-world trip, as George's crazy hairstyle illustrates. But the stress gives already-overworked Eric a mild heart attack.

Eric threatens Robbie with eviction because he thinks he's keeping secrets about Mary. The house is abuzz with secrets and preparations for an elaborate surprise party for Eric's birthday. Johnny drops Mercy on the Camdens' doorstep after Frankie abandons them. Mike trusts Lucy enough to look after his mother for a day, during which the woman surprises her, both by speaking and by what she says.

The Camden family gather together for Matt and Sarah's wedding. Eric and the Rabbi make amends while Ben and Kevin decide to go to Glen Oak to pursue Mary and Lucy. Ruthie and Simon sort out their issues with Robbie.

The Colonel sends a nutty old lady to help the Camdens.

After a scary arrest which could have gone fatally wrong, Kevin decides to leave the police before someone gets hurts as he can no longer concentrate on anything but his young family. Ruthie brings over Meredith and her presumed boyfriend Jack, who proves a natural with babies and a nice senior - too old, so - and is on to her plan; Meredith actually is more interested in the other good boy, Tyler, who agrees with a demure kiss to date. The colonel arrives, winking to Martin about his Iraq veteran dad's gardening job and to Eric's surprise already knows about Charlie - even got and believes Mary's version that Carlos cheated on her, but Carlos explains she just 'caught' him dining with Cecily, the nanny he had to hire because Mary was never home. Simon first scolds, then consoles his ex Sandy for having seduced and made a baby with Martin. Eric spoils the twins fun playing cowboys with granddad because he bans all gun toys and is told to bother about real problems. Lou Dalton tells Eric most parishioners want Lucy fired as his associate pastor.

Colonel John Camden and his wife Ruth are staying over on their way to Hawaii, unannounced. Fearing they will spill the beans, Lucy wants to skip town with Kevin supposedly to help Simon, asking Sandy to cover church service, so she stays in their place with baby Aaron; she's warm to boy-friend Dr. Jonathan Sanderson, chilly to Martin. T-Bone needs help for his first Valentine's day with a girl-friend, Ruthie insists they get matching tattoos, despite his and Margaret's reluctance for permanent markings, having to hide them for the Camdens and a serious needle-phobia. Mac is happy moving into the trio's apartment means 'adult' independence, the girls see domestic misery. When Jane gets her divorce papers from soldier Jack, she wants to wait till after Valentine's day. The grandparents overhear the twins with their parents, and suggest they may soon move for good. Lucy changes her minds and turns up with Kevin.

When they realize that Ruthie has a secret and T-Bone won't talk, the Camden parents fear that her sudden religious interest means something bad, even if their denial of sex is sincere. After some prodding, the twins tell Annie, Kevin drags and bribes out of Mac, Lucy learns from Sandy, and even Eric gets from Margaret and Jane that it's just tattoos--just like Simon, Lucy, and Mary before her, supposedly all unknown to their parents. Again everyone tries to pretend to the others neither to know nor to have told; then the game shifts to guessing who knows what and who, if anyone, should tell Eric..