5.1 – Towers of Silence

First broadcast 18/19 September, 2005.

Still reeling from the loss of Mel and Frankie, what’s left of the team investigates the link between a desiccated corpse found on a scrapped plane, a mutilated body found in Kent, and a robbery at Heathrow Airport.

Notable guest stars: Nina Wadia, David Walliams, Georgia MacKenzie.


The one where… Boyd buys a big model aeroplane (that appears again in the last ever episode, Waterloo).


5.2 – Black Run

First broadcast 25/26 September, 2005.

The team reinvestigate the case of Eddie Vine, an imprisoned ex-police officer Boyd arrested for murder. As suspicions start to rise in the team, Boyd himself is arrested for a crime he has no memory of committing…

Notable guest stars: David Hayman, Diane Parish, Connor McIntyre.


The one where… Boyd gets kicked in the head, and then has his drink spiked with a date rape drug.

5.3 – Subterraneans

First broadcast 2/3 October, 2005.

The discovery of two bodies leads the team to a man whose entire life is built on deception and pretence.

Notable guest stars: Toby Stephens, Nicola Stephenson, Ronan Vibert.


The one where… an inadequate man pretends to be something he’s not and hides out in an allotment shed. And nothing much else happens.

5.4 – Straw Dog

First broadcast 9/10 October, 2005.

Grace’s past comes back to haunt her when Tony Greene launches an appeal against his murder conviction – the one she helped secure in the early days of her forensic career.

Notable guest stars: Tom Ellis, Paul Freeman, Angela Bruce.


The one where… the ’80s police investigation is shown in multiple flashbacks, significant details of Grace’s past are revealed including her affair with Harry Taylor, and the team receives a jar full of severed human fingers.

5.6 – Cold Fusion

First broadcast 23/24 October, 2005.

When new evidence connected to the 1988 Cherry Tree Farm murders comes to light, both Spencer’s prior involvement and the close connection of one member of the CCU team to Commander Will Drake of the ATO make reinvestigating the case a very dangerous gamble.

Notable guest stars: David Calder, Mark Lewis Jones.


The one where… Felix is injured when a bomb goes off in the CCU’s squad room, and Spencer gets shot.