Taylor already confirmed Patient Zero was on the way, hours before unveiling the wider project.
And, like always, fans had been busy decoding a series of cryptic clues.
The 36-year-old megastar confirmed the release date on Tuesday once a countdown on her website finally hit zero.
She wrote on Instagram alongside a new picture of herself in a black halter neck: “I’ve been impatiently waiting to tell you that my brand new single “Patient Zero” will be out on September 25 (!!!!!!!!!!!!) and it’s available to pre-order now on my website for 24 hours.”
It looks like, in true Swift fashion, she had been teasing the track for some time.
The singer’s Opalite music video – released in February – featured a poster with “PATIENT FOR THE ENCORE”, which now makes more sense given the title Patient Zero.
The promo also had four scorecards, each displaying a zero.
Taylor’s Law and Order: SVU cameo at this year’s Emmys also dropped a set of clues that sent fans hunting for meaning. Her four‑word list – “Saccharide. Aries. From the vineyard. North or south” – became the centre of the puzzle, and Swifties later realised the sketch’s third letters spell an anagram of “ENCORE,” echoing a teaser already spotted in her Opalite video.
Before officially announcing Patient Zero, Swift updated her bio, swapping the original line for a version using zeroes: “And, baby, that’s sh0w business f0r y0u”.