Fans of A Song of Ice and Fire, the series of novels which inspired the hit HBO fantasy drama Game of Thrones, have a history of paying an extreme amount of attention to the show’s relationship to the books. You might even say it sometimes reaches the level of a superiority complex, as novel-readers who already know what happens film the reactions of their show-watching friends who are about to be freaked out by what’s onscreen.

The show’s stars are aware of this, and sometimes they exploit it for personal amusement. Take Nikolaj Coster-Waldau, who plays Jaime Lannister on the show. During a press tour for the Scandinavian branch of HBO, Waldau decided to take a prop he happened to find in a hotel room and use it to flummox book readers.

True to form, book fans quickly took to obsessing over this stuffed duck, and Coster-Waldau even got phone calls over the whole thing. So, if you’re a Game of Thrones fan, just know that fans of the books will happily over-analyze just about anything you put in front of them. Use that information as you will, for fun and profit.