The Thin Blue Line

It is the tenth anniversary of Fowler and Dawkins' relationship, but Fowler manages to forget, being instead more concerned with the Queen's Official Birthday.

Habib falls for a fireman named Gary, much to Goody's jealousy, while Fowler finds himself pestered frequently by a man who claims to have committed impossible, solved or extremely historical crimes, much to DI Grim's amusement, until a terrorist begins making threats that cause Special Branch to become involved.

After Fowler drunkenly admits to having kissed Habib during a pub quiz match, Dawkins begins to suspect the two of having an affair behind her back when Grim enlists Fowler and Habib's help in catching a criminal via entrapment.

It's Rag Week in Gasforth, and Fowler and his men are frequently disturbed by teenagers in scary masks – that is until a bank robbery by three men in rag masks occurs while Dawkins is there, leaving it uncertain whether or not the robbery is genuine.

Pestered by his ex-wife, Fowler reluctantly agrees to let his son Bill stay with him and Dawkins for a fortnight. When Dawkins overhears Bill making love to his girlfriend in the bedroom, she becomes envious and attempts to talk Fowler into going to see a sex therapist. Guest appearance by Sheila Gish.

Fowler and Grim clash over their views of handling juvenile troublemakers so they decide to take them on a retreat. Further tension arises when Goody punches a teenage skinhead for racially abusing Habib and is subsequently charged for assault.