It's a beautiful day in Lower Pampling, as the villagers celebrate the final of the C-10 Slam, seemingly unaware - or uninterested - in the murder and mayhem surrounding it. Ben Jones takes a sip of his beer and muses that some things never change in Midsomer county. Three years away and it's like he's never been gone.

Some things have changed, of course. There's another Barnaby, his goddaughter, and that still fills him with wonder and pride. A new pathologist. A new him. Kate will be glad to hear her department is in good hands. He's glad to know Barnaby is in good hands.

He flirts almost reflexively with the new pathologist, mostly to tease Jamie Winter. He's seen how the young DS looks at Dr. Karimore and wonders how this handsome kid in a perfectly pressed suit could possibly be threatened by him. He's got a dozen years on Winter, and the grey in his beard reminds him daily that middle age is just around the corner. But when he smiles ruefully to himself, he doesn't fail to notice Karimore's gaze linger on him, and he knows that a few more laugh lines around the eyes aren't necessarily a disadvantage.

Winter notices as well and quickly finishes his beer. "We should let Ben catch up with the old man and Sarah," he tells Karimore, who doesn't appear fooled in the slightest and hands Betty to Ben with a wink.

"He kept the photo of you from the incident board," Winter says casually. "Didn't think I noticed that he slipped it into his desk drawer. And this week he couldn't even remember my last name." He claps Ben on the shoulder. "Next time call when you're going to be in the area."

It's a warning as much as an invitation, and Ben nods to show he understands. "Shall we go find Mum and Dad?" he asks Betty, rubbing noses with her.

The Barnabys have found a table on the deck and are wrapped up in their own little world. Ben has always admired and envied their intimacy; today it makes him a little lonely, emotions slipping perilously close to the surface.

Sarah waves him over as soon as she sees him, though. She takes Betty from him and kisses him on the cheek.

"I see you chased Jamie and Kam away," she teases.

"Does she know he fancies her?" he asks, watching Winter trail after Karimore like a puppy.

"Does he?" Barnaby asks, seeming genuinely surprised.

"Some detective you are," Sarah replies.

"I'm not interested in my sergeant's personal life," Barnaby says haughtily.

The sheer hypocrisy of it stuns Ben. "You stalked me to find out who I was dating, and then blackmailed me about it," he protests.

"Blackmail is a bit strong," Barnaby says. "The real mystery is how you managed to stay undercover for two months without running into a dozen ex-girlfriends."

"I have a forgettable face," he replies. And nowhere near as many ex-girlfriends as Barnaby likes to think, unless you count failed first dates.

"Leave poor Ben alone," Sarah scolds. "You'll send him running before we have a chance to spend any time with him." She turns to Ben with a gleam in her eye. "I'll invite them to dinner tomorrow. You can keep Jamie on his toes. Sweet boy, but a bit too sure of himself."

Dinner sounds lovely. There's a lot still to do before he can go back to Brighton, and he knows he owes the Barnabys a proper visit. "Are you matchmaking, Mrs. Barnaby?"

"Not at all. Though pathologists and detectives do make good partners, don't you think?"

He thinks about Kate back in Brighton and smiles. "I don't know what you're talking about."

Even Barnaby rolls his eyes at that. "Let poor Ben drink his beer in peace," he mimics, earning a smack on the arm from his wife.

As he sits there listening to the Barnabys bicker good-naturedly, he tries to shake off the last remnants of Jack Morris and settle back in his now unfamiliar skin. It's been two months of playing someone else, and the return is a bit disorienting. It helps to have John and Sarah there, grounding him; his beautiful goddaughter to play peekaboo with; Paddy lying by his feet, hoping for treats. He doesn't have to go straight back to being DI Jones. He can just be Ben for a while.

Melody Henderson walks outside with Serena Luthando and Cilla Troughton, and he hopes that there has at least been some healing amidst all the hurt. Serena glares at him, reminding him that he's been part of that hurt. As if he could forget.

It's the worst part of being undercover; making good people believe he's something he's not in order to catch bad people, building trust and friendships under false pretenses. Melody was a good friend to him, making him welcome in Lower Pampling, helping him solidify the outlines of his cover. She didn't deserve his deception.

He feels awkward and embarrassed, but he knows he can't just let her walk away without saying something. "Mel," he calls out, standing up. He senses Barnaby's disapproval, but he's never been able to separate himself personally from an investigation. He starts to head towards her, but stops when Serena puts her arm around Melody and tries to steer her away.

Melody shakes Serena's arm off and walks over to him. "Cilla says her mother killed Leo and Fitz. That she was going to kill you." To her credit, she looks concerned about him. She's a kind woman, and while Ben doesn't understand how Leo could have cheated on her, he does understand why he would spend the next 20 years trying to make it up.

"I'm a hard person to kill," he says with a smile, though if Barnaby hadn't triangulated his cell phone, he might have been another notch on Germaine's cricket bat.

"Because you're a policeman," she says flatly, kindness only going so far in the face of betrayal and grief. There was no one to rescue her husband at the last minute. Perhaps if he'd been quicker at making the connections, he might have been able to protect Leo. But it's hard to spot someone not fixing a match, and the murders hadn't been about his case in the end.

"I am," he says, realizing there was a lilt of a question in her words as well. "Detective Inspector Ben Jones. I was investigating match fixing in C-10."

"That's how Leo paid for the cruise. He took money to throw the match."

He wants to offer her some comfort, to preserve her good memories of her husband. "Because he loved you. And he didn't go through with it." He doesn't know if that will help or hurt even more. It's not why Leo was killed, but it easily could have been.

"It's all a terrible mess. I can't believe Wade would do that, ruin his own sister's family." She gazes sympathetically back at Serena. "Kia is devastated."

It's a humiliating reminder that he didn't even solved his own case - Causton CID tracked down Kia's IP address to make the final connection that broke the ring. Barnaby and Winter flushed Wade out of hiding. At least he was bait to catch the killer, however unwittingly.

She looks back at him, her expression no longer sympathetic. "You lied to me," she says. "You used me."

It's true and it's not. He took advantage of her vulnerability to get into her home and search for evidence, but he'd genuinely wanted to console her. It's not a distinction that will matter to her, though. "I'm sorry," he says, knowing the words are inadequate. Serena had been right to warn him off.

When her hand twitches, he knows what will happen even before she does, but doesn't make a move to avoid the palm that cracks against his cheek. She doesn't linger to see him stagger from the blow. In truth, it wasn't that hard a hit, more a point than a punishment, but it's enough to awaken the concussion that had been muffled by adrenaline and euphoria.

"Steady on," says Barnaby in his ear, and the hand on his elbow does just that for him.

"I deserved that," he says ruefully, rubbing his cheek to take the sting away.

"Probably," Barnaby replies, undoubtedly believing the worst of him and women, as always.

"I didn't sleep with her," he says, defending his tattered honour.

"Of course not."

Ben can't tell if he's being serious or mocking, but then he never could read John Barnaby, even without a concussion muddling his thoughts. He rubs his face again, then drops his head, blinking. He's surprised when he feels an arm around his shoulders.

"Come on," Barnaby says quietly. "Sit down before you fall down." He leads him back to the table and pushes him into an empty lawn chair.

"I told Kam you shouldn't be playing," Sarah scolds. "Let me get you a glass of water and an ice pack." She glares at her husband. "You should have taken him to hospital, John."

"He's a grown man, Sarah. He's perfectly capable of taking himself to hospital, if he needs to."

But Ben can see and hear the guilt. "It's just a bump on the head," he tells them both.

"Honestly, you men. You think you're made of titanium." She hands Betty to Ben, pointedly ignoring her husband, and stalks back to the bar.

Betty's head tucks into the crook of his neck with the complete trust of a toddler, and he wraps his arms around her in a cuddle he needs far more than she does. When she reaches up and gently twirls a lock of his hair with her fingers, he thinks he might cry.

He hears a click and looks at the smartphone in Barnaby's hand.

"Another one for the family album," he says cheerfully, tapping on the screen. Sarah's phone pings on the table. "Don't worry," Barnaby added with faux innocence. "I won't send it to Kam. Have to give Winter a fighting chance."

"That's very sporting of you, sir." The "sir" slips out as naturally as the sarcasm.

"Come now, Ben. Surely, we can dispense with the formalities. You're an inspector now, not my sergeant."

He can't imagine calling Barnaby "John", but he likes the sound of his own first name coming from the older man. "You still outrank me."

"That's true." Barnaby pulls his chair around so he's facing Ben. "Since you're feeling deferential, you won't mind me putting Sarah's mind at ease." He leans forward, studying Ben's pupils. "Track my finger," he orders, moving his index finger in front of Ben's eyes.

"Do you actually know what you're looking for or are you just doing what you've seen on telly?" Ben tries to roll his eyes, but it hurts more than he's willing to admit, so he settles for a long-suffering sigh. "I'm just a bit dizzy," he says. "You know what it's like coming down from the adrenaline. The team trainer checked me out before he let me bat."

Barnaby doesn't look convinced, but he leans back, gives him some space. He squints slightly, and Ben knows he's cataloguing symptoms, but he's saved from further prying when Sarah returns.

She coos when she sees Ben snuggling Betty, and reaches for her phone, smiling when she sees the picture Barnaby sent. "Oh, lovely," she says. "My new wallpaper. I'll forward this on to your Gran, Ben. She'll be tickled. Shall I send it to you as well?"

She shows him the photo and he blushes. It would get him laughed out of the station, but he doesn't care. "Send me an email. My phone got the worst of it today."

Barnaby exchanges a glance with Sarah, and Ben knows neither of them believe he made it out unscathed.

"I found some paracetamol," Sarah says, handing him two tablets and a glass of water. "Take these now and we can get something stronger for you once we get you settled at home."

"No arguments," Barnaby says, when Ben starts to protest. "Your landlady's been arrested, remember? Jack Morris is homeless, and I don't think Melody is going to let you stay the night this time."

"No wonder she slapped you," Sarah exclaims. "Jack Morris was a cad."

"I slept on the sofa!" He knows she's just teasing him, but he still feels guilty. Even that scumbag Butler Styles thought he was moving in on Melody. It doesn't matter that he'd had entirely different intentions from what everybody assumed. They still weren't pure.

"It's easy to get a rise out of someone when you accuse them of something they'd never do," Barnaby points out.

"There's the psychology I've missed," Ben retorts.

"I don't need a psychology degree to know that you're a good man." He nods at Sarah to take Betty and holds out his hand. "Come on. I don't want to have to explain to your DCS that I let you keel over on my patch."

Ben lets him pull him up and is glad that Barnaby has hold when his head swims. Adrenaline crash, concussion. The beer probably didn't help. It's all mixed up in a pounding headache that the paracetamol is only just beginning to touch. It's been a long day, with good results all round, but there's always a price to pay.