[6] Lanthier's first book, a middle grade novel called The Mystery of the Martello Tower, was published by HarperCollins Canada in 2007 and nominated for a Snow Willow Award.

In 2008, HarperCollins Canada published the sequel, The Legend of the Lost Jewels, and the Ontario Library Association's Canadian Materials Committee named it to that year's "Best Bets - Fiction Books for Kids" list.

Both The Mystery of the Martello Tower and The Legend of the Lost Jewels follow the adventures of heroine Hazel Frump and her younger brother Ned.

Lanthier has said the books’ settings, "Ile du Loup" and "Frontenac", were directly inspired by Wolfe Island, Ontario and nearby Kingston.

An afterword explains the concept of freedom of expression and the work done by PEN and other charities on behalf of writers and journalists at risk in countries around the world.

Selected authors and illustrators participate in events and activities held in hundreds of schools, public libraries, bookstores and community centres across the country in all provinces and territories.

Heather Reisman, bestows featured placement in hundreds of stores nationwide including Indigo, Chapters and Coles.

The following month the Ontario Library Association's Canadian Materials Committee named it to the OLA's 2012 "Best Bets" list.

[17] In April 2013 The Stamp Collector won The Society of Children's Book Writers and Illustrators' Crystal Kite Award - Americas Division.

Each member of The SCBWI is allowed to vote for their favorite book from a nominated author in their region that was published in the previous calendar year.