"The other wife" by Michael Robotham

An audio book

Joseph, a psychology prof who has Parkinson's and whose wife died a year before, has 2 daughters - one 12 (who's being threatened with expulsion from school), one at Oxford University. He gets a call from a hospital. He rushes there - his father (a domineering retired doctor with a wife and 3 kids) is in a coma in acute care. At the bedside is Olivia Blackmore, who says she's been his wife for 2 decades. She's covered in blood. She says she found him at the foot of their stairs, bleeding. Joseph notices that he has week-old bruises too. He's never seen Olivia before. After she's questioned by the police she shows him around their house. Each detail reveals an unknown aspect of his father.

He discovers that his mother's known about Olivia from the start and that both Olivia and his mother have lied about their alibis.

The pace slows as his father's financial difficulties (fraud?) emerge. Joseph asks Kate, a police-woman, out. He talks to the wife of Olivia's late husband, whose death begins to look suspicious.

A mad man with a knife get in his house threatening the girls and him. The man runs away. Joseph suspects he's Olivia's son, Ewen. He is, but he's not Joseph's half brother.

Ewen's made to do bad things by his friend Mica. There's a tussle, Olivia's injured, and in self defence Mica is killed.

For decades, Joseph's father has been sending £40k each year to an address. Joseph discovers that Bethany, a woman brain-damaged from birth, lives there with an aggressive brother. Joseph's father was investigated about the case. He got off, but only because the family solicitor self-sacrificingly destroyed evidence.

He acts on something that Kate told him in confidence which results in her suspension.

The family lawyer's been sleeping with Olivia.

The attack on Joseph's father looks like a botched contract killing. It emerges that he asked Bethany's brother to kill him so that the insurance could pay off his debts. But in the end it's the family lawyer and his wife who were defrauding. Joseph talks the wife out of suicide.

I like the writing. Not so sure about the book. More could have been made about Joseph's reconstruction of his father (and father-child relationships in general).