"The Drowning Hour" by SK Tremayne

An audio book.

The narrator, Hannah, 28, a brand manager, lives in "The Stanhope" a newly re-opened luxury hotel on an island in East Anglia. She's haunted by a past event that we're gradually told more about (often a bit at the end of a chapter). She has a younger beautiful sister Cat and a boyfriend Ben. There are 2 timelines: the present (Hannah) and the days around the disaster (Cat)

She learns from a guest that there's a woman at the hotel who's so scared of water that she never leaves the island. He says the management want to get rid of her. The woman he's talking about is Hannah. There was a party that got out of hand after Cat skinny-dipped. The narrator told the inquest that she wasn't involved, but she was. The drowning hour is when the estuary riptide becomes dangerous.

Her therapist visits - useful for info-dumping. Her mother died young. Her father's infirm. She and Cat spent their gap-years together, travelling.

She saves a drowning dog but that doesn't cure her fear of water. She can only keep the dog if she lives in the usually deserted East wing. She's seen a face at a window there. She has a plan that she could take sleeping pills and booze to knock herself out, then Ben could get her onto the mainland.

Part of her job is to squelch the online rumours and hashtags about the hotel. The adverse publicity becomes so bad that they suspend operations. The internet attacks are coming from someone with access to the hotel's database.

Actually Cat's dead. Hannah has been in denial. Her sudden admission of the problem is surprising, as is the minimal reaction by those who know her. Her therapist tells her to use the discussions with the imaginary Cat as clues to help her learn what happened on the fateful day. She discovers that Ben had sex with Cat on that day, and not for the first time. Maybe in room 10, East wing. Maybe this is the room where her mother was unfaithful too. Who left the note for help there?

The 2 timelines continue in parallel, Cat's 3rd-person treatment surprisingly muted. Cat got drugs from the receptionist. She met the son of the man whose father had an affair with her mother on the island. He made her think that her mother didn't die of cancer. After she had sex with Ben, the son blackmailed her - revenge for her mother wrecking his family.

A minimum of staff is retained - 4, then 3. Hannah uses the dog, a Tarot card and texts from Cat (still arriving and immediately deleting) to work out what happened on the night and what happened to her mother. She suspects Cat killed herself because of guilt about Ben and because she thought their mother killed herself through guilt.

Hannah finds hidden camera in rooms (thanks to a tarot card). She realises VIPs, police, etc have been videod having sex here, then blackmailed. She realises that the wifi (through which all mobile messages also go) is minitored). She phones the ex-cook for info. She's alone on the island now. She sees a boat, men with shotguns, she thinks she's going to die in the water, then escapes with help from the cook, etc.

In the final chapter (months later) she's on holiday with the cook (now her fiance) and Cat. She's chatty with Cat but intends to say goodbye to her forever.

Too many unlikely events. Why did the owners leave cameras and networks around after they left? Wouldn't a room for VIPs be quite smart? Wouldn't strangers be conspicuous in a quiet area? And Hannah's deductive powers are more than impressive.

Other reviews

• Oxford bookworm (the twist regarding their phone conversations and the current whereabouts of her sister is irritating, undermines an otherwise sinister story, and makes Hannah an unreliable narrator. I’m still a big fan of Tremayne’s first novel “The Ice Twins” but this one is not for me.)