Few books have captured our collective attention quite like the Fourth Wing series, and the latest instalment, Onyx Storm, is no exception. Author Rebecca Yaros released the third instalment in the Empyrean Series into the world on 21 January and, safe to say, we devoured it. But if you've reached the very cryptic Onyx Storm ending and have been left with a few questions, you're certainly not alone. Below, we're diving into exactly what went down at the end of Onyx Storm, and compiling every leading theory about what it could all mean for the characters' futures.

Warning: Spoilers ahead. 

What is Onyx Storm actually about?

First things first, let's get the basic plot details out of the way. Continuing the story from the first two books, Fourth Wing and Iron Flame, it follows a trainee scribe turned dragon rider, Violet Sorrengail. She's a student at Basgiath War College, where she's training to be a dragon rider. Outside the school's walls, however, the evil Venin are closing in on Aretian, and Violet must venture out to seek allies and protect the people and place she loves.

What happens at the end of Onyx Storm?

At the climax of Onyx Storm, Violet is coming to grips with the fallout of an intense and devastating battle. The book ends with Violet awakening in the Riorson House courtyard with a wedding ring made from a Riorson family heirloom on her finger, and a note from Xaden, her love interest. However, the note instructs Violet not to go looking for Xaden.

Further complicating things, Violet soon realises she has no memory of the past several hours. She turns to Imogen, who possesses the ability to erase memories, and asks, "What did you do?" to which Imogen responds, "What you asked me to." In other words, it looks like Violet requested her memories be erased, though the reasons behind this decision are not immediately apparent.

So, what exactly does the ending of Onyx Storm mean?

Unsurprisingly, the ending of Onyx Storm leaves several key questions unanswered, allowing for multiple theories about what really transpired and leaving room for future revelations.

First, many have speculated that Violet requested her memories to be erased to protect her loved ones. Given the high-stakes nature of the ongoing war, some readers believe that Violet might have chosen to erase specific memories to keep vital information from falling into enemy hands. This theory hinges on the idea that whatever she witnessed — and can no longer remember — contains secrets that could jeopardise those close to her if they were uncovered by the wrong people.

Another theory relates to Violet’s sudden and mysterious marriage to Xaden. Some readers speculate that the marriage is part of a political or strategic alliance, meant to strengthen their position against a larger threat. It's also possible that Xaden is distancing himself from Violet for her safety, or to keep her from learning something too dangerous.

And finally, the character of Imogen has raised suspicions among many readers. Some theories suggest that Imogen might not have acted alone in erasing Violet’s memories, or that there may have been an ulterior motive behind it.  Others wonder if there’s a larger, more complex plan at play—one that involves manipulating Violet’s memories for a larger purpose, potentially to steer her into a new direction or force her to confront a dangerous truth.

Love Fourth Wing? Read up on everything we know about the upcoming television adaptation (including who fans think is cast as Xaden).