The death of a scientist on the side of a live volcano proves a difficult case to crack for Humphrey and his team when everything appears to point to a death from natural causes.

The Saint Marie Literary Festival is rocked by the death of young literature student and Florence’s childhood friend, Esther Monroe, when she is discovered at the bottom of a cliff on the opening day.

Humphrey and Martha’s romantic weekend retreat to a remote island is cut short when Charlie Taylor is found dead in his room at Hotel Cecile.

The president of the Saint Marie cricket club is found shot dead in the middle of the team's ground. As the sun rises over the island, suspicion falls on his teammates.

A murder investigation propels the team to London in pursuit of their suspects.

The team race against the clock in London to solve two murders, after their prime suspect is found dead. Meanwhile, Dwayne has an emotional encounter and Humphrey finds that some advice from an unexpected source helps him come to a big decision.

When a tourist claims to alibi a woman convicted for murder eight years ago, the team are forced to reopen the case.