In the six months following the death of A.S.A. Harrison last April, the Toronto author and artist’s posthumous debut novel, The Silent Wife, has become a bittersweet success story for its publisher, Penguin Canada.

Since its release in June, foreign rights for the psychological thriller, which follows the disintegration of a marriage, have been picked up in 10 territories. The book has sold more than 20,000 print and digital copies in Canada, maintaining a steady place on the Canadian-fiction bestseller list. In the U.S., The Silent Wife just entered its 10th week on The New York Times‘ paperback trade fiction bestseller list.

According to Penguin Canada senior editor Adrienne Kerr, Harrison “ who worked on The Silent Wife for 10 years before it was published “ knew her novel was poised for international success, and was aware of endorsements from authors Kate Atkinson and Elizabeth George.

She had a sense that the book was going to be very well received, says Kerr. But she had no expectation that it would become as big as it did.

The Silent Wife follows on the runaway success of similar titles such as S.J. Watson’s Before I Go to Sleep and Gillian Flynn’s Gone Girl. Kerr says early comparisons to Gone Girl, which has spent more than a year on major bestseller lists and is now being adapted for film, prompted readers to pick up Harrison’s novel.

We knew there was a tremendous appetite for psychological suspense, and we knew that this book was astonishingly good for a debut novel, Kerr says. Readers have responded to its psychological acuity “ it’s a really astonishing portrait of a marriage in crisis. What I find so remarkable about it is that it is clearly the product of a very precise mind. Her writing is razor-sharp.

Word-of-mouth and book-club sales have been strong. What we could do in the absence of having a spokesperson for the book was to let readers and Canadian retailers speak on its behalf. Readers have really taken on this book, says Kerr.

A public memorial to celebrate A.S.A. Harrison’s life and the success of The Silent Wife is scheduled at the Art Gallery of Ontario on Oct. 11 from 7 p.m. to 9 p.m.