Stephanie Garber Returns to Once Upon a Broken Heart Universe

Stephanie Garber is returning to the world of Jacks and Evangeline Fox. As confirmed in Beautiful Books' May 2026 Marginalia news roundup, Flatiron Books has announced and published The Mirror of Infinite Endings — a new novella set in the Once Upon a Broken Heart universe — in 2026.

According to New Books Alert, the title is the fourth installment in the Once Upon a Broken Heart series and is scheduled for a September release.

According to the official Flatiron Books series page, The Mirror of Infinite Endings picks up after Jacks and Evangeline Fox have reached their happily ever after — and proceeds to complicate it. The publisher's description notes that the story is set in the Magnificent North, and that while everything appears to be going well, at least one secret is being kept.

The novella features cameos from fan-favourite characters and twenty full-page illustrations by the artist Lotusbubble. Flatiron is also releasing a deluxe collectible edition of the first book in the series alongside the new title — that edition includes an illustrated slipcase and hardcover, illustrated endpapers, limited-edition stencilled edges, and the previously unpublished fairytale "The Ballad of the Archer and the Fox," per the same Flatiron series page.

Stephanie Garber is the author of the Caraval trilogy and the Once Upon a Broken Heart series, both published by Flatiron Books. The Once Upon a Broken Heart series — which follows Evangeline Fox and Jacks, the Prince of Hearts, through a world ruled by ancient beings called Fates — is part of the same fictional universe as Caraval, as noted by Bookish Wayfarer.

The series is a #1 New York Times bestseller, according to the Flatiron series page. The illustrations for the novella are provided by Lotusbubble, whose work features across all twenty full-page interior spreads.

The first book in the Once Upon a Broken Heart series established Evangeline Fox as a protagonist whose pursuit of love draws her into a bargain with Jacks, the Prince of Hearts — with escalating consequences across subsequent volumes. Liberty Patriot Press previously reported on the series' expansion, noting that Garber announced a third installment in September 2022.

The new novella extends that continuity into a fourth entry. Per The Bean Workshop, Garber's books have already been translated into more than thirty languages, and The Mirror of Infinite Endings is confirmed to launch simultaneously in Brazil, Germany, Greece, Hungary, Italy, and Poland — a coordinated international release that the same outlet reported as notable for a novella-length title.

For an assessment of the first book in the series, see LuvemBooks' review of Once Upon a Broken Heart.

The September 2026 release window, flagged by New Books Alert, means the novella arrives alongside the deluxe collectible reissue of book one — giving booksellers and readers two distinct entry points to the series in the same season. The simultaneous multi-country launch, as reported by The Bean Workshop, will be a concrete measure of the series' international publishing footprint.

Full pre-order and retailer details are available via the Flatiron Books series page.