Chicago, Illinois - Taylor Swift had quite an epic show in store for fans at night two of The Eras Tour in Chicago!

You know it's been a good night on The Eras Tour when "I AM DONE WITH TAYLOR SWIFT" trends on social media well into the next day.

On Saturday, the 33-year-old delighted Swifties with a special guest during the surprise song portion of the evening as she welcomed country star Maren Morris to the stage.

The duo sang an acoustic version of You All Over Me, a vault track from Swift's re-recording of Fearless.

While Morris mainly performs backup vocals in the studio version, she showed off her talent by taking the lead on the second verse during the live performance.

Swift had nothing but praise for the I Wish I Was singer, telling the crowd Morris is one of her "favorite artists."

The Anti-Hero artist even made the surprising confession that "nobody knew" if Fearless (Taylor's Version) would be "a success or a very embarrassing project." With many of the re-recorded tracks now surpassing the streams of the originals, it's safe to say the project has been a success.

But the duet wasn't the only shocker of the surprise song portion, as Swift then took to the piano to perform a track many fans didn't even realize was a possible choice!

Sending every Swiftie tracking the albums of the surprise songs into a panic, Tay surprised attendees with a stripped-down performance of I Don't Wanna Live Forever.

And which era is that from again? Well, that's a bit complicated.

The track was released in 2017 as a duet with Zayn Malik for the soundtrack of Fifty Shades Darker, making it Swift's first non-album surprise song of The Eras Tour.

As fans collectively freaked out about the unexpected choice, many swiftly jumped to conclusions about what the performance could suggest about her upcoming re-recordings.

I Don't Wanna Live Forever came out two years before Scooter Braun obtained Swift's masters, which he then sold in 2020, and it was released under Big Machine Records, so it's safe to say she plans on re-recording it so she can own it.

The Lavender Haze songstress has previously re-recorded several songs she's made for movie soundtracks, including Today Was a Fairytale, which was released with Fearless (Taylor's Version), and Eyes Open and Safe & Sound, which were retroactively added to the Red (Taylor's Version) era.

Based on its release date, the most likely home for a re-recorded I Don't Wanna Live Forever is Reputation (Taylor's Version). Here's hoping Malik makes a return for the track!