I was thirteen the first time my brother tried to kill me.

These days, Della is a loving wife, a dedicated teacher, a woman trying to do her best. She has put her past far behind her. But she hasn't forgotten the lessons she learned.

It's just a regular morning when Della welcomes Zoey to her English class. She treats her like any other new student: assigns her a desk, hands out the work. But then she meets Zoey's cold, calculating eyes and freezes as terrifying memories threaten to overwhelm her.

Della knows what evil looks like when it hides behind a confident smile. Her own brother, the town's darling, couldn't keep his true nature hidden for ever. Della has been watching out for people like him ever since, determined to stop them before it's too late.

When a student is viciously attacked and Della is sent a detailed account of the crime, she's more convinced than ever that Zoey has darkness inside her.

But to make people believe her, she needs proof. Will she risk everything to get it? And without it, can she be sure she's right?

Prepare to be hooked by this dark, gripping crime thriller, perfect for fans of Karin Slaughter, Gillian Flynn and Rachel Caine.

Readers absolutely love What I Know:

"I devoured this book in one sitting. Got my heart racing, atmospheric, chilling and utterly gripping... Fantastic... nail-biting... one of the best books I have read this year. A MUST READ " Goodreads Reviewer, ⭐⭐⭐⭐⭐

"Boy did I enjoy it My heart was racing throughout... I didn't relax until the end. And what an ending it was ' Goodreads Reviewer, ⭐⭐⭐⭐⭐

"A page-turner if I've ever read one I picked this up when I was having trouble sleeping and literally did not put down until I was finished several hours later... The twists were unpredictable and whoa ... everything I love in a great thriller " Goodreads Reviewer, ⭐⭐⭐⭐⭐

"WOW Hooked from the first chapter and couldn't put it down... Excellent " Goodreads Reviewer, ⭐⭐⭐⭐⭐

"Enthralling Captivating One of the best page-turners I've read this year ... It will suck you in and keep you there from start to finish... a great summer read " Goodreads Reviewer, ⭐⭐⭐⭐⭐

"FANTASTIC... kept me on the edge of my seat. I was hooked from the very first page... so many twists and turns... I sped through this in one sitting" Goodreads Reviewer, ⭐⭐⭐⭐⭐

"Full of twists... Loved it Perfect reading." Goodreads Reviewer, ⭐⭐⭐⭐⭐