Book review, I See You by Clare Mackintosh: a clever thriller takes a train journey to a shocking destination

Mackintosh’s second novel will make edgy reading on your morning commute

The journey to work plays into the hands of a dangerous voyeur in this psychological thriller

Commuting. It’s a daily chore for so many and something you don’t much think about (unless you’re a Southern Rail customer and then you think of little else). You just do what you can to get through it: iPad perhaps, paper, seat by the window – if you’re lucky. What we don’t imagine, in all that sweaty, claustrophobic tedium, is that someone is watching us, making notes.

Clare Mackintosh has picked exactly this creepy scenario as the context for her second psychological thriller I See You.

Zoe Walker, a forty-something mother of two teenage kids, is on her way home from a job she hates. When she eventually bags a seat she flicks through the evening paper to find a picture of herself looking up from the less savoury columns of the personal ads, with just a website address – findtheone.com. It throws her, as it would anyone.

Once home, her family all try to persuade her it is nothing but a freaky coincidence. The picture is not of her at all. But she knows, and we know and some sinister third party who speaks in italics knows, that it is. Shortly afterwards Zoe sees a similar ad, only this time with the picture of another woman. When that woman is days later found strangled in Muswell Hill, Zoe is on the phone to the police PDQ.

She is lucky to find a champion in Kelly Swift, a disgraced detective who has been sent to the gulag of transport policing for some heinous misconduct (she whacked a child molester during an interview) and who badly needs her shot at redemption. With Zoe’s lead about the classified ad, Kelly gets it and elbows her way back on to the murder investigation.

As the computer boffins burrow their way into findtheone.com, it appears that the site is refreshed each week with details of a new entry: a woman who is simultaneously pictured in the paper. For a hefty premium visitors to the site receive a listing containing minute details of her daily commute, including what she wears, which ticket machine she uses at the station, where she sits on the train, and ends up with a suggested rating: easy, moderate, difficult.

Is it a bizarre dating tool? The unseen orchestrator in italics gleefully enlightens us: findtheone.com is a way of making introductions between commuters, “a helping hand to bring people together”, which sounds benign – but isn’t.

Mackintosh builds a convincing and complex emotional backstory for both women throwing enough teasing red herrings to leave us vaguely suspicious of everyone in their lives. In Zoe’s case, her boyfriend isn’t all he says he is, her kids are a handful, her ex is devoted but odd and her boss is a monster. But there are also constants: her best friend, café owner Melissa, is a rock who helps keep her grounded.

As the two women race to track down findtheone.com’s sinister editor before anyone else winds up dead, the business of going anywhere on a train becomes fraught with dangerous possibilities. This clever and plausible thriller is one with which it is all too easy to relate. Your fellow commuters might be just that, or then again, they might not. The daily schlep to work will never be quite the same again.