The Stepsister’s Secret

She’s family now. But can I trust her?

When my stepsister Alison moves in to look after my mother, everyone in my family is grateful. Alison’s a nurse, and she says she just wants to help. But I don’t trust her.

Years ago, when Alison and I were the same age as my own son Isaac, I made a terrible mistake that tore Alison’s world apart. I hoped she didn’t realise, but the look in her icy blue eyes tells me: she knows exactly what I did.

I’m certain she’s responsible for my mother getting weaker. I don’t like the way she’s pushing me out, isolating me … and getting way too close to my husband, Nick.

I’m watching her. And I’ll do anything to keep my family safe. But I have no idea just how much danger we’re in…

A totally unputdownable, twisty story of family secrets that have deadly consequences. Perfect for fans of Shari Lapena, Freida McFadden, and Daniel Hurst.

What readers are saying about Karen King:

‘Wow, I could not put this down… I devoured it in one sitting… Had me hooked from the first chapter…. Left me speechless… kept me guessing until the very last page!’ Arcreviews_by_m, ⭐⭐⭐⭐⭐

‘Omg I absolutely loved this book and couldn’t put it down! Full of suspense, shouting out loud noooooo or wtf moments! Highly recommend.’ NetGalley reviewer, ⭐⭐⭐⭐⭐

‘HOLY SMOKES! You will not want to put this book down. Talk about a gripping story. I could not get enough of this.’ NetGalley reviewer, ⭐⭐⭐⭐⭐

‘Cannot give this book enough stars!!!… I was actually annoyed I had to go to uni and stop reading it for a few hours… Absolutely outstanding.’ Itsa.bookstory, ⭐⭐⭐⭐⭐

‘Excellent… Full of brilliant twists and turns… WoW… Superb… guessing till the very end! Excellent!’ Goodreads reviewer, ⭐⭐⭐⭐⭐

‘Wow… Absolutely brilliant. I couldn’t put it down… A real page turner.’ Goodreads reviewer, ⭐⭐⭐⭐⭐

‘One of my favorites of 2025… An amazing fast-paced thriller that you can read in one sitting.’ Nath.readingadventures, ⭐⭐⭐⭐⭐

‘Mind-blowing read. Loved it.’ NetGalley reviewer, ⭐⭐⭐⭐⭐

‘Brilliant… just mind-blowing…. I was hooked… It’s just superb.’ NetGalley reviewer, ⭐⭐⭐⭐

‘An absolute rollercoaster, packed with thrills and suspense.’ Goodreads reviewer, ⭐⭐⭐⭐⭐

‘So many twists and turns that I never saw coming… Couldn’t stop reading it.’ Goodreads reviewer, ⭐⭐⭐⭐⭐