With more than 150 years under his belt, there’s a great deal about Vampire Diaries hunk Damon Salvatore (Ian Somerhalder) that we don’t know. We were reminded of this fact with the reveal that Damon was once an Augustine vampire, aka a lab rat experimented on by the vampire-hating secret society. Just how did Damon fall into the Augustine Society’s clutches? We speculate below!

What we know

Though we’ll presumably learn much more about the experiments once performed on Damon in the name of vampire science in Season 5, Episode 9 (“The Cell”), right now, all we know is this: in 1953, Damon was taken prisoner by the Augustine Society, one of many vamp lab rats used in a project aimed to create a vampire that feeds on vampire rather than human blood for survival. Damon was kept in a small, stone cell where he etched his initials and the year into the wall. In the promo, we see scientist tell a strapped-down Damon, “This is for the advancement of science,” before snapping his neck. Not cool, dude.

Damon’s timeline

Though we were previously unaware of any of Damon’s activities in the 1950s, we know what he was up to in the 40s and 70s. In the former, he was hanging in New Orleans, trying to break cling-on Charlotte’s sire blonde to him. While there, he reunites with Stefan and Lexi, the former of which is ready to ship out to serve as an Allied soldier in World War I. Damon decides to go with him, but Lexi talks him out of it. Stefan is doing well (aka controlling his Ripper tendencies), and Lexi thinks Damon will be a bad influence. Stefan ships out without him, and we don’t catch up with Damon again until the 1970s.

In the 1970s, Damon is living in NYC with his humanity switch firmly set to the “off” position. Upon Stefan’s urging, Lexi spends six months with Damon trying to convince him to turn his humanity back on and become a responsible vampire (aka non-killer). Damon tricks her into falling for him, then leaves her on a roof. It’s a pretty terrible move, but now we’re thinking Damon’s decision to turn off his emotions could have had something to do with his time as an Augustine vamp. This doesn’t justify his treatment of Lexi, but it certainly puts it in a more understandable context.

How did the Society nab Damon?

This still leaves the question of how Damon managed to fall into the Augustine Society’s clutches. There’s the Mystic Falls connection to consider: Whitmore College isn’t far from Damon’s hometown, and the Society seems to have some Founders Council connections. Could Damon have fallen prey when visiting the old homestead? Another possibility is that the Society lured him in either with the promise of something (a cure for vampirism?) or the threat against someone he cares for. Did the Society pretend to have Stefan, one of the only people who Damon will consistently try to rescue? Or, probably more likely, the Society first nabbed Damon’s friend, Enzo

Though we have yet to meet Enzo, we know that he was a victim of the Augustine Society’s experiments while Damon was. He is described as an old friend of Damon’s. Did they become friends while they were both Augustine vampires? Or were they friends before their capture, lured in one after another? Whatever Damon’s Augustine vamp backstory, we can’t wait to hear it especially if it helps explain some of his terrible behavior over the years.

How do you think Damon became an Augustine vampire? Did his time as a vampire lab rat cause him to switch off his humanity? Share your theories in the comments below!

Catch the next episode of The Vampire Diaries on Thursday, December 5 at 8 p.m. ET on The CW.