First broadcast 11/12 July, 2004.
The team hunt for an enduring serial killer with a particularly macabre method of dispatching his victims – hammering a nine inch nail through their skulls.
Notable guest stars: Michael Byrne, Geoffrey Bayldon, Clive Wood.
The one where… Boyd makes that joke about nine inches meaning a lot to a guy.
First broadcast 18/19 February, 2007.
Boyd is sent a dagger from New York, which relates to a case Mel was looking into just before she died. As they investigate a murder from the ’40s, the team are temporarily joined by Sarah, a Mossad agent who tracks Nazi war criminals.
Notable guest stars: Michelle Forbes, Eileen Atkins.
The one where… the wartime plot is shown in black and white flashbacks, and Boyd gets romantically entangled with Sarah.