Don discovers he's been left a house from his recently deceased grandmother, only to find out it has huge back payments and a strange man who won't leave. He decides to get a lodger to help with the rent - the girl he was in love with as a teenager.
Don goes on a field trip with Abby and the kids from her school. This attempt to show her he's a good, decent man goes horribly wrong when he gets the 10-year-olds drunk in a country pub.
Don finds out he's legally obliged to put on a wake for his deceased nan, with an open casket for her body. The only problem is that he cremated her a few days before, so he and Eddie audition old people at an elderly centre for the role of Don's nan.
Don meets a girl who is nine years younger than him whilst working as a charity street collector. He hangs out with her and her friends, but soon realises he's not the hip young dude he once thought he was.
Don starts a new job employed at Karl's father's company. The two find themselves competing against one another to be the best. Don sees Glen as a father figure.
Things don't go as planned when Don goes out on the pull with Eddie. Don finds out that Abby is single again when he returns home and he ends up upsetting the girl he met whilst out.
With Abby having been gone for about six months, Don and Eddie both want different women to move into the spare room. They decide to take them both out to decide who should get the room.
After Don starts dating a much older woman he finds it hard living in her grown up world. Sam becomes friends with a man from the university who is caught going through her draws by Don.
With Sam dating a musician, Don's musical side is awakened. Soon there is a rivalry between Jackson and Don.
Sam invites her brother, Jamie to stay for the weekend. Jamie ends up in Don's bed following a heavy drinking session. When Don decides to find out if he is gay he asks Jamie to go to a gay bar with him.
So that he can prove to Sam and Eddie that he's fit Don decides to join a local gym. Don finds it much harder than he thought and passes out after a go on a running machine. After he decides that the gym isn't for him he decides to have colonic irrigation instead.
Don wants Sam to pretend to be his wife for the day when he has to attend an old friend's wedding. Don's friend though is not the same as he was like at school.
Don finds it hard to cope knowing that he blew his chance with Sam and now that she is dating somebody else it just makes him feel worse. He ends up coming up with an elaborate story about an imaginary job to make himself feel better.
Don starts to date a girl called Jenny, but her mood swings cause problems. When the couple join Sam and Brian's team at a local pub quiz in an attempt to beat arch-rival Derek things end up coming to a head.
Don manages to get himself and Jason a double date for him while conducting a tour of a new exhibition at a gallery. Don's girl Felicity ends up inviting them away for the weekend to her parents' country estate.
Don finds himself having a bad start to the week when he notices that his hair is thinning, He ends up booking an appointment with a specialist to discuss having a hair transplant. Things get worse for Don when he notices that he isn't the centre of attention after he is completely ignored he storms out. After Eddie discovers Don's letter about the transplant he ends up assuming the worst. Eddie, Sam, Brian and Mrs Treacher attempt to support Don when they think that he doesn't have long left to live and Don ends up making the most of the situation.
Don ends up surprising himself after he takes pity on pretty homeless woman called Susan. Sam ends up suggesting that he ask her out. When Sam returns home with Brian, she discovers Susan sitting on the sofa in their living room whilst Don runs her a bath. The following day Don doesn't want Susan to leave but after he offends her on a day out he tries to make it up to her by getting to know her friends better.
Don learns that Brian is going to ask Sam to marry him and realises that he still has feelings for Sam. Eddie suggests that Don sees a therapist where he ends up taking the therapist into his confidence and confessing his feelings for Sam, as well as some slightly shocking habits. Sam decides to throw a fancy dress party to celebrate Brian's birthday. Don feels unnerved when he learns that his therapist has come along in fancy dress. Don tries to find him at the party to stop him from revealing any of his secrets.
Don waits to find out if Sam is going to agree to marry Brian and becomes agitated. He ends up joining Eddie's amateur dramatics group to try and take his mind of things. Don attempts to convince Sam to take the part after the leading lady is injured. Don has this one last chance to try and impress Sam.
The Danbury household are preparing to celebrate Christmas and Don is making a final, desperate effort to lead a normal life. He has to deal with an out-of-control OAP though and a violent Santa.