The Last Word finds Sussex private detectives Natalka and Benedict on the trail of a killer in a writers' retreat.

Natalka and Edwin are running a detective agency in Shoreham, Sussex. Despite a steady stream of minor cases, Natalka is frustrated, longing for a big juicy case such as murder to come the agency's way.

Natalka is now living with Benedict. But her Ukrainian mother Valentyna has joined them from her war-torn country and three's a crowd. It's annoying to have Valentyna in the tiny flat, cooking borscht and cleaning things that are already clean. To add to Natalka's irritation, Benedict and her mother get on brilliantly.

Then a murder case turns up. Local writer, Melody Chambers, is found dead and her family are convinced it is murder. Edwin, a big fan of the obit pages, thinks there's a link to the writer of Melody's obituary who pre-deceased his subject. The trail leads Benedict and Edwin to a slightly sinister writers' retreat. When another writer is found dead, Edwin thinks that the clue lies in the words.

Seeking professional help, the amateur investigators turn to their friend, detective Harbinder Kaur, to find that they have stumbled on a plot that is stranger than fiction.