The Butterfly Assassin

Available now from Simon & Schuster Children’s Books

The cover of The Butterfly Assassin by Finn Longman. In the centre is a butterfly. One wing is bright yellow, and splattered with paint like graffiti. The other is bright blue. The title is superimposed over the butterfly in white text. Above the butterfly is the tagline, reading "Innocent by day, killer by night", and above that is a quote from Chelsea Pitcher, author of This Lie Will Kill You, reading "An electrifying debut!". The author's name is at the bottom. The cover is black, with grey graffiti-like squiggles creating texture.

Innocent by day, killer by night: a dark, twisting thriller about a teen assassin’s attempt to live a normal life.
Trained and traumatised by a secret assassin programme for minors, Isabel Ryans wants nothing more than to be a normal civilian. After running away from home, she has a new name, a new life, and a new friend, Emma, and for the first time in Isabel’s life, things are looking up.
But old habits die hard, and it’s not long until she blows her cover, drawing the attention of the guilds – the two rival organisations who control the city of Espera. An unaffiliated killer like Isabel is either a potential asset . . . or a threat to be eliminated.

Will the blood on her hands cost her everything?

From Finn Longman, an exhilarating new voice in YA fiction, comes a blockbuster new series for fans of global phenomena The Girl with the Dragon Tattoo, Killing Eve and The Hunger Games.

Where to buy The Butterfly Assassin:

UK and Ireland:

Chains etc:

Indie bookshops I know and like:

Signed copies can be ordered from Housmans (international shipping available) — a radical non-profit independent bookshop :)

*These are affiliate links, so it’ll earn me a small commission if you order through them. You won’t be charged any extra.

Australia and New Zealand:

Published by Simon & Schuster AU: Amazon AU | Booktopia | Angus & Robertson | Mighty Ape | Readings | Dymocks | QBD Books

France (ebook 5 October, paperback 26 October):

Published by Bragelonne, translated by Alison Jacquet-Robert: Amazon FR | Decitre


Amazon US (e-book and audiobook only)

You may also want to check out my introductory post with FAQs, or this post about Isabel’s asexuality and the issue of representation.

Content Warnings

This book contains:

  • on-page depictions of murder, death, and associated violence
  • descriptions of poisoning and associated symptoms, including vomiting
  • hospital scenes and references to past medical abuse/non-consensual surgery
  • flashbacks to and discussion of past child abuse (physical and emotional)
  • brief references to spiders (not described at length)
  • liberal use of swear words

It does not include any sexual content, including sexual violence.

I’m happy to provide more details or warnings to those who need them, so please ask if you have any questions or concerns.