The "Red" singer, 24, posted a clip of her finger tapping desperately on the 18th floor of an elevator along with the caption: "So, here's your first clue..."
Many fans, and Billboard, agree that the singer's message is definitely related to the release of a new single and possibly a new album. Swift is known for teasing clues about her upcoming projects on social media before explaining what they actually are.
The singer's mysterious post comes just a few days after it was revealed that she is planning an "explosive" performance for the upcoming 2014 MTV Video Music Awards. Given that the "I Knew You Were Trouble" singer hasn't released any new music since her 2012 album Red, all signs seem to point to one conclusion -- she secretly has been working on a new project.
Billboard also points out that Swift has historically released most of her albums in or close to October.
Whether the 18 refers to the number of days until she makes the final announcement, or the actual release date of an upcoming single or album... we'll have to wait to find out.