Nicci Gerrard and Sean French both studied English Literature at Oxford University at the same time but it was not until much later in 1990 that they teamed up as both a couple and the formidable writing duo they are today.

Nicci and Sean began work on their first joint novel in 1995 and adopted the pseudonym of Nicci French. They released Blue Monday in 2011 – their thirteenth novel together and What To Do When Someone Dies was published in 2009.

Unusually for Nicci French the conceptual development of the book, What To Do When Someone Dies, did not follow their normal writing process.

“Quite often when we write we have a concept for the whole book but with this one we had the idea of the opening scene but we just couldn’t get it out,’ explains Nicci. “We were excited by the idea of a wife waiting for her husband to return home from work and a policeman knocking on the door saying he’d been found dead, in a car with another woman who she’s never heard of. The implication is he’s had an affair and what should she do next. How does that unravel? How does that turn into a thriller? and that’s where we started from.”

Next Nicci French decided they wanted to write about a woman who was grief-stricken, trying to deal with the issue of how much she could trust her dead husband and how to deal with shattered memories.

“In a way we wanted to have a thriller that was compelling in terms of plot’, says Nicci, “that also goes through those stages of loss, anger, shock, numbness and finally, acceptance.”

Episode 1

Schoolteacher Ellie Manning hears the devastating news that her husband Greg has been killed in a car accident, and her grief is compounded when police tell her that Greg did not die alone - another woman, Milena Livingstone, was in the car with him. Faced with the shattering knowledge that Greg was having an affair, Ellie is determined to discover everything she can about Milena. Ellie's best friends Gwen, Fergus and Joe rally round to help, but are unable to stop her obsession with the woman who died with Greg.

Episode 2

Ellie goes to Milena's workplace using a fake name and offers to help sort through Milena's paperwork on the pretence of being helpful - but really looks for clues as to how Milena knew Greg. Milena's business partner Frances Shaw confides in Ellie that her own marriage is over as she had fallen for Milena's lover. When Ellie asks Frances who her lover was, they are interrupted but agree to meet later at the office to talk. However, when Ellie return, she realises that she is too late.

Episode 3

Ellie is taken by surprise when Milena's husband turns up offers her a firm clue to what happened on the night of Greg's death. Having risked everything and with nothing left to lose, Ellie is determined to get to the truth, whatever the cost to her personally.

This DVD will be available later

Photograph shows Anna Friel in character for ITV's drama series Without You starring her and Marc Warren