New · Crime Stopper Kids Mysteries · Book 3

The Italian Diamond Heist is on its way.

Book Three of the Crime Stopper Kids Mysteries, for ages 10–13. Join the newsletter to be first to know the day it’s out.

A modern-day Famous Five meets City Spies.

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The Con Artist's Takeover book cover: Book Two of the Crime Stopper Kids mystery series for ages 10–13The Italian Diamond Heist, Book Three of the Crime Stopper Kids mystery series, cover coming soon

The Crime Stopper Kids Mysteries

Middle-grade mysteries for ages 10–13, best read in order, starting with Book 1. A free bonus prequel comes with the newsletter.

Start with Book One About the series

The Adventures of Crimson and the Guardian

An orphan servant girl, a talking unicorn named Crimson, and a kingdom to save from the evil Lord known as the Snake. Fantasy for ages 9–13.

For fans of Ranger’s Apprentice and Wings of Fire.

Start with Book One About the series

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The Runaway Rescue (a free mystery) plus fantasy fact sheets for young writers: dwarves, elves, unicorns and dragons.

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Karen Cossey, New Zealand children's author of mystery and fantasy books, beside a flowering pōhutukawa tree

Hi, I’m Karen.

I write adventure and mystery books for middle-grade readers all over the world. My two series are The Adventures of Crimson and the Guardian (fantasy) and The Crime Stopper Kids Mysteries.

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