Toni’s boss, the founder and head of Oxenford Medical, and a virologist developing a drug to combat a lethal virus.

Stanley’s estranged son, a gifted computer engineer and former employee whose gambling debts and resentment propel him toward another theft.

A quiet Oxenford Medical laboratory technician whose disappearance, infection, and concern about animal testing trigger Toni’s initial investigation.

A professional thief who approaches Kit and leads the ruthless team recruited for the planned breach of Oxenford Medical.

Toni’s former boyfriend and police colleague, now a local police superintendent whose history with her creates personal and professional tension.

Stanley’s daughter, Tom’s mother, and Ned Handley’s fiancée, who hopes Christmas will secure Ned’s commitment and introduce his daughter properly.

Stanley’s other daughter and Miranda’s sister, married to Hugo and arriving at the Christmas gathering with their children.