Cat Hogan returns to West Meath upon her mother's sudden death - she has an accident at home and died (or was it an accident?). Blood is about old secrets, older betrayals, mind games and the lies family tell each other.

Cat struggles to get her suspicions taken seriously after her mother's mysterious death. She tracks down an old friend from her past who may be able to shed light on the present.

The day of the funeral arrives and the extended family gather to bury Mary. Jim reintroduces a strange and distant relative to the household.

In the aftermath of the funeral, Cat finds herself on the receiving end of Jim's apparent mercy.

Reeling from the impact of another tragedy, Cat is presented with a dark choice to make, depending on whether she seeks the truth, or revenge.

The story returns to the days leading up to Mary's death and the truth is finally revealed. But will it satisfy Cat?

Season start. Jim Hogan is determined to atone for his mistakes and reunites with his family. But when the whole family gathers around Fiona, who was involved in a car accident, information that threatens to split the family once again.

Fiona tries to recall what has happened in recent weeks, while being questioned about the discovery of her husband's dead body. A look back shows Jim and Paul witnessing an abuse by gang leader Kian.

Paul has to choose between helping Kian or protecting his friends. Police Dez Breen continues the interview with Fiona while Jim's attempt to rebuild his life encounters a hardship when he fails in a job interview.

It's time for the twins' first communion and the entire Hogan family is gathering for the first time since last year's dramatic events. There is tense mood within the family and Jim must fight to prevent Paul from breaking down.

After talking to Jim, Dez feels that he is starting to approach the truth about what happened to Paul. A look back shows Paul worried about Fiona leaving him and how it would be too much for him to handle.

Season finale. Fiona is interrogated again by Dez and she tells the police how shortly before Paul's death she received a bad message about her health, and how that information in combination with Kian's pressure became too much for Paul to handle.