The mysterious death of a wealthy confectionery firm owner plunges Nikki, Leo and new recruit Jack Hodgson into a murky world of corporate subterfuge.

When two women close to a dead businessman are murdered, Nikki, Jack and Leo open his family's skeleton-packed closet.

The murders of two women in a house basement force Jack to lock horns with an old flame, while Leo wrestles with providing a second post-mortem on a baby.

As the basement women case highlights two cooperating killers, Nikki, Jack and DI Reed realise one victim was killed by a controlled sedative.

When arrested and interrogated by DI Kate Warren, Alan Lane vehemently protests his innocence and insists he didn't kill his wife.

Nikki is wooed by a science minister as she and Jack investigate a murder on an eco-building project, whilst Leo finds himself trapped in a hospital siege.

Conflict brews between Leo and Nikki when he suspects her new boyfriend is involved in a 50-year cover-up, leaving Leo battling alone to expose the truth.

Human remains found on an Afghan water supply project send Leo, Nikki and Jack to the war-torn region to establish if it is a missing British soldier.

Leo develops a life-changing relationship with a charity worker as Nikki and Jack make a forensic breakthrough on their case in Afghanistan.