Cover of The Mortal Word

The Mortal Word

core novel 2018 The Invisible Library

Record

First published2018
Original language EN
Work typenovel
Canon statuscore
Reader rating4.19 (14,458 ratings, collected 2026-08-26)
First-edition ISBN9780399587443
Internal chronology5

Synopsis

The Mortal Word, the fifth book in the Invisible Library series, begins as Irene returns to London from a book-theft assignment in Germany and is immediately pulled into a far more delicate crisis. The Library is quietly mediating a peace conference between the warring dragon and Fae courts, and the dragon delegation's second-in-command has just been murdered, threatening to collapse the fragile negotiations entirely. Irene and her detective ally Vale travel to an alternate 1890s Paris to investigate, uncovering signs that the victim may have found evidence of treachery among the Librarians themselves. With several Librarians, including Irene's own parents, held hostage by the dragon and Fae courts as insurance against failure, Irene must determine whether the killer is dragon, Fae, or one of her own colleagues, all while trying to keep the peace talks from falling apart.

Where it sits

Notes

  • From the series record (The Invisible Library): An eight-novel sequence following Irene, a spy-librarian who collects works of fiction from alternate versions of Earth for an interdimensional Library.

Neighbouring works

Publication order and internal chronology are tracked as two separate orderings, but they resolve to the exact same sequence for this book, so one combined line is shown instead of two identical ones.

Sources

← The Invisible Library dossier · All universes

Part of the Library. Fields without an identified source are omitted, never guessed.