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1. The Accident That Changed History by Trygvasson

   Fandoms: Harry Potter - J. K. Rowling  

   • Mature
   • Graphic Depictions Of Violence, Major Character Death
   • Gen
   • Work in Progress

   11 Jan 2026

   Tags

   • Graphic Depictions Of Violence
   • Major Character Death
   • Sirius Black
   • Bellatrix Black Lestrange
   • Alastor "Mad-Eye" Moody
   • Narcissa Black Malfoy
   • Rodolphus Lestrange
   • Avery Jr. | Severus Snape's Schoolmate
   • Mulciber Jr. | Severus Snape's Schoolmate
   • Severus Snape
   • James Potter
   • Lily Evans Potter
   • Fleamont Potter
   • Euphemia Potter
   • Lucius Malfoy
   • Abraxas Malfoy
   • Regulus Black
   • Walburga Black
   • Orion Black
   • Cygnus Black III | Walburga Black's Brother
   • Remus Lupin
   • Peter Pettigrew
   • Antonin Dolohov
   • Nott Sr. (Harry Potter)
   • Tom Riddle | Voldemort
   • Black Family (Harry Potter)
   • Black Family Drama (Harry Potter)
   • Black Family Madness (Harry Potter)
   • Dysfunctional Black Family (Harry Potter)
   • POV Sirius Black
   • Sirius Black Needs a Hug
   • sirius black is a death eater
   • Sirius Black is a spy
   • Morally Grey Sirius Black
   • Or possibly morally Black
   • Manipulative Albus Dumbledore
   • Alastor "Mad-Eye" Moody is So Done
   • Insane Bellatrix Black Lestrange
   • Protective Bellatrix Black Lestrange
   • Narcissa is the perfect Slytherin
   • Regulus Black Needs a Hug
   • Sirius Black & James Potter Friendship
   • Severus Snape Being a Little Shit
   • Sirius Black is Not Okay
   • First Wizarding War with Voldemort (Harry Potter)
   • abuse of the Imperius curse
   • Abuse of Transfiguration
   • alternative universe
   • but not necessarily better
   • Inferi (Harry Potter)
   • Mass Casualties
   • when in doubt murder the problem
   • You get the idea

   Summary

   Sirius Black always got away with bullying Snape, until the one time things went too far, and he didn't. Expelled halfway through his seventh year at Hogwarts, his first job offer is dangerous to refuse, from his cousin Bellatrix. Sirius is the one who ends up as the Order's double-agent in the First Wizarding War. And dear lord, does that make a huge difference in the course of wizarding history...

   This is rated for violence. Lots of it.

   Language:

   English

   Words:

   267,207

   Chapters:

   62/65

   Comments:

   96

   Kudos:

   194

   Bookmarks:

   75

   Hits:

   11,463