Neither of them is sure when it happened- when they went from being two separate people to being one, from Sam and Gene to SamAndGene. When people mention them these days it's always in the same breath. Gene catches himself bringing the tape recorder into Lost-And-Found with him. Sam realizes one day that he can tell a single malt whiskey just by taste when he never even drank whiskey back in 2006. When Roger Whitaker comes on the radio he doesn't automatically change the station, and he catches gene listening to T-Rex one late night t the office. They're rubbing off on each other, there's no denying that. They still end up shoving each other against walls, and the fights have been known to rattle the windows of CID, but more often than not they're a united front, albeit an extremely argumentative one.

They've created a weird sort of connection, this pseudo-friendship/partnership thing. They're more intimate with each other than with almost anyone else. Sam has told Gene things that he hadn't told Maya, things he hadn't even told his mum. Gene has shared things with Sam that he had long thought forgotten, buried things he wouldn't dream of saying to Chris, to Ray. Sam has introduced Gene to Indian food, not just cheap curries but real actual food. Gene discovers that despite his avowed hatred of anything not drenched in fat and grease, he kind of secretly loves lentils. Sam has learned to appreciate the comfort a bacon buttie can offer, even though he still whinges and wrinkles his nose at anything in a chip wrapper and muttering about cholesterol.

Gene realizes in October 1974 that he's spent more ours at the station than he has at home. He's had more meals with Sam than he's had at his own kitchen table. He's seen Sam more in the past three weeks than he's seen his missus. A few days later when she serves him the papers and leaves to live with her sister in Hull, Gene isn't surprised.

When Sam comes into CID on Monday he looks like shit. There was a fire, someone says, and Gene pieces together that it must have been electrical, hearing snippets of conversations about broken tellies and a bottle of lager. Whatever happened, Sam's out of an apartment and living in a motel.

Gene isn't sure what makes him offer Sam the spare room. He isn't sure when he started caring about his DI's wellbeing or why he suddenly won't take no for an answer. No matter what the reason is, a day later Sam is sitting at the kitchen table when he gets up in the morning, looking for all the world like he owns the place. It's odd, Gene thinks, that Sam seems to fit into the space so well; it's almost like he's always been there, munching his cornflakes, reading the paper.

He doesn't tell the soon-to-be ex-missus that Sam's moved in, but she finds out soon enough when she comes back to retrieve the forgotten wedding gifts. Sam's stayed late to finish some paperwork, so he isn't there when gene comes home tired from a long, hard day of work (a murder inquiry, the victim an eleven year-old girl) to see his wife on the sofa, sobbing into one of Sam's shirts. He'd left it out to dry the night before beside Gene's, complaining about the state of the laundry. Gene finds himself insisting that it's not like that, but she doesn't believe him and, to tell the truth, he's not sure he believes himself. Because if you define a relationship by its most basic elements- if going out for dinner is a date, if being ready to die for someone is love- then maybe he really has been cheating on the missus.

Gene starts to notice after that. He's aware suddenly of how much he and Sam touch- a casual arms around the shoulders, a brush of fingers when Sam passes him his tea, pats on the back, the contact of fist against stomach. At the Railway Arms, Sam's smile is drunk and easy, a murder prevented, a blag foiled. At the kitchen counter at 3 AM, fixing himself a pot of coffee blearily, on edge for reasons Gene doesn't understand. It seems that insomnia is contagious, because Gene will come down sometimes in the wee hours of the morning and sit down on the sofa beside his DI to stare at the test pattern. If it's before 2 AM they'll talk; if it's any later than that they'll just sit there in silence.

They grow into each other, intertwining like the roots from two different trees.

Neither of them is sure when it happened- when they went from being two separate people to being one, from Sam and Gene to SamAndGene. On the morning that Gene wakes up to see Sam sleeping beside him, he feels the same way that he did when he first saw Sam at his kitchen table, the same way he feels when they've put away a criminal. He feels the same way he did when Sam kissed him, finally, the same way he felt when he first saw him in CID that cool September morning eons ago.

It's right.