SenLinYu Books: Alchemised, Underbelly and Their Fan Fiction

SenLinYu has published one novel, Alchemised (2025), which reworks their Harry Potter fan fiction Manacled into an original world, and the short story “Underbelly” (2026), set in the same world. Before that came fan fiction: 54 works on AO3 as of December 2024, now hidden from readers who aren’t logged in.

Below you’ll find SenLinYu books in order, what the author has shared about themselves in interviews, and what they have said about the next novel. Everything here is spoiler-light.

SenLinYu Books at a Glance

Title	What it is	Released	Status
Manacled	Harry Potter fan fiction, 370,515 words	April 2018 to August 2019	Removed from AO3 on January 1, 2025
Alchemised	Debut novel, 1,040 pages	September 23, 2025	Hardcover, ebook and audiobook
Alchemised, Deluxe Three-Volume Slipcase Edition	The same novel in three hardcover volumes	October 13, 2026 (US and UK)	Same text in a new format
“Underbelly”	Short story set in the Alchemised world	October 1, 2026	In Grimdark Magazine #48
Second novel	The second book in a two-book deal	Not announced	No title or date yet

Who Is SenLinYu?

SenLinYu is a pen name, used for everything the author writes and often shortened to Sen. According to the author, “Sen Lin Yu” means “forest rain”. On AO3 the handle is senlinyu. SenLinYu is nonbinary and uses she/they pronouns; we use they/them here.

Background They Have Shared

In interviews, SenLinYu has described growing up near Portland, Oregon, in a large, conservative Christian family, where all the children were homeschooled. Their mother, a former professional ballerina, died when they were in their late teens.

They are half Japanese, and their mother’s family was interned during World War II. They studied the classical liberal arts at a Christian college, and today they live in Portland with their family.

How SenLinYu Started Writing

SenLinYu started writing in early 2018, drafting in the Notes app on their phone. By spring they were posting fan fiction: A Slow Cruel Descent went up in April 2018, and the first six chapters of Manacled were posted on April 27, 2018. They finished Manacled on August 19, 2019, and its final count stands at 77 chapters and 370,515 words.

Manacled became the second-most-read work on AO3, with BookTok surges during the pandemic and again around September 2023. SenLinYu and their publisher now say the author’s online works have passed twenty million individual downloads. For a spoiler-free overview of the fic itself, see our Manacled book page.

Alchemised: SenLinYu’s First Novel

Alchemised is SenLinYu’s first novel and so far their only one. They began redrafting Manacled around Christmas 2022, signed with the agency WME in 2023 (their agents are Caitlin Mahony and Rivka Bergman), and announced the book on February 5, 2024. Emily Archbold at Del Rey acquired North American rights in a two-book deal, and Rebecca Hilsdon at Michael Joseph acquired the UK rights.

The novel came out on September 23, 2025, from Del Rey in the US, Michael Joseph in the UK, Australia and New Zealand, and Penguin Random House Canada. A few facts worth knowing:

• Format: a single 1,040-page volume, a standalone in English.
• Audiobook: read by Saskia Maarleveld, 36 hours 15 minutes.
• Translations: the publisher says it is published in twenty languages.
• Sales: a first print run of 750,000 copies, and the publisher now advertises over one million copies sold.
• Bestseller lists: #1 on the New York Times Combined Print & E-Book Fiction list dated October 12, 2025, and a #1 debut on the Publishers Weekly hardcover fiction list.
• Content: an adult book. SenLinYu’s own content warnings include sexual assault, rape, self-harm, medical torture and eugenics.

The story keeps Manacled’s shape but moves it to Paladia, a city-state where magic is replaced with alchemy. Hermione becomes Helena Marino, a healer, and Draco becomes Kaine Ferron, the High Reeve. Our Manacled vs Alchemised guide covers what changed.

SenLinYu has described the book’s themes as “trauma and survival, legacy, and the way that love can drive one to extreme darkness”. They have also been firm that you can start with the novel: “Stop telling people that it’s necessary to read Manacled before reading Alchemised.” If you are wondering what happened to the fic, our guide on where to read Manacled explains its removal and the legal options now.

The Deluxe Three-Volume Edition

A Deluxe Three-Volume Slipcase Edition is due on October 13, 2026, in the US and UK. It divides the same novel into three hardcover volumes, with:

• slipcase art by Wylie Beckert;
• foil stamps by Francesca Baerald and Alex Hovey;
• silver edges and ribbons;
• color endpaper maps of “The Known World” and “Paladia” by Francesca Baerald;
• 24 illustrations by Avendell, 12 of them new.

Avendell is an illustrator and a friend of SenLinYu’s. Manacled’s AO3 listing credited Avendell as its illustrator, and every English hardcover of Alchemised includes one black-and-white interior illustration by Avendell.

“Underbelly”: A Short Story in the Alchemised World

SenLinYu’s newest published work is “Underbelly”, a short story set in the world of Alchemised, written to mark the novel’s first anniversary. It appears in Grimdark Magazine #48, published on October 1, 2026, in print and as an ebook, including on Kindle. It is original fiction, so it is not on AO3.

SenLinYu has said readers of the novel “will recognise some names and faces”, and warned that the magazine’s brief was “the darker and grittier the better, and feel free to lean into the horror.” Our guide to Underbelly by SenLinYu covers where to buy it and whether to read Alchemised first.

SenLinYu’s New Book: What They Have Said

No title or release date has been announced for SenLinYu’s next book. Here is what is known:

• There is a second book under contract. The Del Rey deal was for two books.
• They were working on it in 2025. In September 2025, SenLinYu was reported to be “already working on their second novel”.
• They are not sharing details yet. In a post marking the book’s first anniversary in September 2026, they kept writing news to themselves, saying “if I speak too soon, I may jinx myself.”

We haven’t seen anything confirming whether the second novel is set in the Alchemised world, so treat any rumor about it as unconfirmed.

SenLinYu Fanfics

SenLinYu had 54 works on AO3 as of December 2024. Today, logged-out visitors to their AO3 profile see none of them. SenLinYu limited their AO3 works to registered users, partly because of AI scrapers and partly because, as they have said, taking part in the fandom was being “misconstrued” as endorsing J.K. Rowling’s anti-trans activism. The details below come from the listings before that change.

Fic	Pairing or premise	Length and status	Notes
Manacled	Hermione/Draco	77 chapters, 370,515 words; complete	Removed from AO3 on January 1, 2025
Let The Dark In	Hermione/Draco, in a world where Voldemort never rose	35 chapters, 184,658 words; in progress	45,291 kudos and 2.12 million hits by December 2024
All You Want	Hermione/Draco; Eighth Year, Omegaverse	36 chapters, 172,650 words; complete	Rated Explicit
Love and Other Misfortunes	Part-Veela Draco	23 chapters, 98,584 words	First posted on FanFiction.net in 2018
Do Not Go Gentle	Hermione/Snape	10 chapters, 34,435 words	Not a Dramione fic
A Slow Cruel Descent	A captured Order intelligence chief	Posted April 2018	Has a sequel, A Fragile Ascent
Forever Is Composed Of Nows [James/Aurore]	Set after Manacled	One-shot, October 2019	Its title names characters from late in Manacled, so read it after finishing
Cordial Enemies	Co-written with Stargazing121	In progress	A joint work

Other titles on their AO3 list include A Thing With[out] Feathers, The Library of Alexandria, The Seduction, Anthology and Compendium. Outside Harry Potter, they also wrote Star Wars (Reylo), Avatar (Zutara) and Squid Game fan fiction.

SenLinYu has restricted fanbinding of their work to personal, non-commercial use, so any printed copy of their fics offered for sale is unauthorized.

The Influences SenLinYu Has Named

Manacled began with the first episode of Hulu’s The Handmaid’s Tale. For Alchemised, SenLinYu has named a longer list:

• Fiction: Mary Shelley’s Frankenstein, their most constant influence; Shirley Jackson’s The Haunting of Hill House, their model for the house as a character; Kurt Vonnegut’s Mother Night; Mary Doria Russell’s The Sparrow, without which Helena might not have been a healer; Mansfield Park, whose Fanny Price was a model for Helena; The Secret Garden; Jane Eyre; and Wuthering Heights.
• Nonfiction: Svetlana Alexievich’s The Unwomanly Face of War, their key research text for the war and for women’s erased labor, and Lawrence Principe’s The Secrets of Alchemy.
• Anime: Fullmetal Alchemist, Fate/Zero, Castlevania and Frieren, the last an influence on Luc, Harry’s counterpart.

Our list of books like Manacled groups these with other read-alikes and explains what each one shares with the story.

If you’re new to SenLinYu, sample before you commit to 1,040 pages: the prologue and Chapter 1 of Alchemised were posted free on the author’s newsletter in 2025, and the publisher offers a free sample too. Reading with friends? Our Manacled discussion questions include a set that compares the fic with the novel.