The seventh season of Game of Thrones was plagued by problems and plot holes.

Few of the season’s storylines proved quite as disappointing as its handling of Littlefinger (Aidan Gillen). The season sees the notoriously intelligent schemer get brought to his knees by Sansa (Sophie Turner) and Arya Stark (Maisie Williams), who ultimately have him executed. While that endpoint makes sense for Littlefinger, the way that Game of Thrones plotted out the story — namely, by showing viewers a fake feud between Sansa and Arya — left a lot to be desired.

Fortunately, one fan theory suggests that author George R. R. Martin may have Littlefinger meet his end in The Winds of Winter in a much different way.

The Theory — On Reddit, u/HuangZhou speculates that Littlefinger won’t be killed by Sansa and Arya in Martin’s Song of Ice and Fire books, but by Lady Stoneheart, the name given to an undead Catelyn Stark. The Redditor argues that Littlefinger will, much like he is in Game of Thrones, be put on trial and summarily executed for his crimes against the Stark family.

However, if this theory is true, it means Martin will have Catelyn Stark serve as both Littlefinger’s childhood savior and his eventual executioner.

Littlefinger’s Weakness — In both Martin’s books and Game of Thrones, Littlefinger harbors a lifelong love for Catelyn Stark.

His adoration even results in him challenging her fiancé, Brandon Stark, to a duel when he’s still a teenager. Predictably, it doesn’t go well for Littlefinger, whose life is spared solely because Catelyn asks her betrothed not to kill him. The event only strengthens Littlefinger’s love for Catelyn and creates a hatred for the Starks that goes on to play an instrumental role in Martin’s books.

Littlefinger is involved in the murder of Catelyn’s husband, Ned Stark, and after Catelyn’s death he takes on her oldest daughter, Sansa, as his protégé. While Sansa becomes the new target of Littlefinger’s affections, she remains a pawn in his schemes, which exposes her to even more manipulation and secrecy.

Making Littlefinger’s killer Lady Stoneheart, a being consumed by her thirst for revenge, would therefore be the kind of ironic twist that Martin is a master at pulling off.

The Inverse Analysis — Right now, most Song of Ice and Fire fans seem to agree that it’ll likely be Sansa Stark who ends up orchestrating Littlefinger’s demise in the books. Martin has provided enough evidence to suggest as much, and making the daughter of Catelyn Stark Littlefinger’s executioner does have a fateful, acidic edge to it.

But Martin is also an author capable of surprising his readers in a way that few other writers can, so there’s always a chance that Littlefinger’s death will play out in The Winds of Winter in a very different way than fans expect. Having an undead version of Catelyn Stark be the person who kills Littlefinger would make for both an unexpected twist and a fitting way for the character to go out.

The Winds of Winter will be released whenever George R. R. Martin finishes writing it.