Actress Amanda Abbington sparked speculation that her Sherlock character could be leaving for good as filming on series four came to an end.
Amanda, who plays Mary Morstan, the wife of John Watson (played by her real-life husband Martin Freeman), tweeted that there had been a "golden wrap on Mary" along with a picture of a ring on top of a call sheet.
While "to wrap" on a show just means to finish filming, a "golden wrap" is a special term for the farewell given to an actor when they bow out of a show.
It's unclear whether the "golden" was just a reference to the ring she'd placed on top, which, in a later tweet, she made evident was not Mary's wedding ring, hopefully putting a damper on theories that a divorce from John could be on the cards at least.
At the end of the last series, she and John were expecting a child, which adds even more mystery to what could happen in the fourth series.
The cryptic tweet left fans wondering whether this meant the end for her character.
Amanda's character has already outlived her literary counterpart.
If following cannon, Mary dies sometime between Sherlock's apparent death in The Final Problem - adapted as The Reichenbach Falls, the final episode of series two, in the show - and his return three years later.
In an interview with the Telegraph in 2014, Martin admitted that he expected Mary to die in the show.
"While we play fast and loose with the original stories, we generally follow the trajectory of what Conan Doyle did. So he (John) gets married, and then Mary dies - so at some point presumably she'll die."
If Mary does meet her end in series four, fans can expect that the former assassin will not go quietly.
The new series will air on BBC One in 2017.