Rich Little Liars by AJ Carter

Everyone has something to hide…

After surviving a house fire that killed her husband, Kelly Reynolds vanishes into the East Hamptons, a world of gated estates, pristine lawns and neighbours who smile like they have nothing to fear. Here, money buys discretion, and the past is supposed to stay buried.
But when anonymous notes begin appearing at her door, Kelly realises someone knows what really happened the night of the fire. With each message, the East Hamptons’ flawless façade starts to crack, and the quiet judgement in her neighbours’ eyes feels less imagined.
As suspicion tightens and danger creeps closer, Kelly’s carefully rebuilt life begins to unravel. Because some secrets don’t stay hidden – and the truth is far more dangerous than the lies that protect it.

Rich Little Liars is a gripping, edge-of-your-seat read that twists and turns its way to a shocking conclusion.