Welcome to Eldey, an island with deadly secrets.

Mona is a carefree artist, staying at The Cloister to work on her illustrations.

Beth is the harried mother of a toddler, on the remote Welsh island for a weekend escape with her family.

Charlotte wanted a romantic getaway with her husband, not a trip with his troubled teenage stepdaughter.

One of them is a serial killer who poisoned three of her friends at her eleventh birthday party.

When one of the hotel guests is found dead, it becomes clear to Mallory Dawson – the night manager of the boutique island hotel and former police detective – that The Birthday Girl is among them.

Three guests who fit the profile, but which of them would risk everything to kill again?

Six lies killed Huw Jones.

On New Year’s Eve 2010, Huw Jones disappeared from his bedroom while his father and five friends were downstairs. His body was later discovered on the nearby cliffs at St Non’s.

That night, all six friends lied in their statements to the police.

Over a decade later, Huw’s mother, Heledd is found dead.

Mallory Dawson must uncover the lies lurking in the tight-knit community of St Davids. But someone has kept their secrets for years, and they would kill to protect them…

Everyone in the family had a secret. Which one has proved deadly?

When Mallory Dawson gets a call from a former colleague, Elsa, describing a strange scene, she initially thinks nothing of it. The teenage cleaner had gone into clean a holiday cottage in the forest to find a kettle boiling on the Aga, sandwiches half made and the family who were renting it gone.

DI Harri Evans, however, has a story about the place from the time he was in uniform. He was called out to a girl with scratches down her face claiming someone unseen had attacked her.

When the father of the missing family is found dead in their hire car there is an urgent hunt for the rest of the family. But their identities are false and there’s no hint of their history. How are the past and present connected?

The sins of the past have not been forgotten…

Pippa Evans had been a teacher at Penbryn Hall for just one week when her body was found alongside evidence of a pill overdose. Going undercover at the private school, investigator Mallory Dawson senses something rotten behind the wealth and privilege. Someone is leaving her coded messages: but do they want to help or harm the case?

Mallory soon finds links to the Solstice Sisterhood: a religious cult that believed punishment was cleansing. When a pupil is savagely attacked on school grounds, there is suddenly no time to lose in finding the killer.