The core of Star Trek is the exploration of outer space by Starfleet on behalf of the Federation, something that earned the Federation a lot of friends and many enemies. One of their greatest enemies were the Changelings, who sent out 100 of their young to explore the galaxy centuries earlier. But what happened to the vast majority of them was never resolved by the end of the series, leaving a huge mystery for fans.

A science-fiction series is only as good as its villains, which is particularly true of Star Trek: Deep Space Nine. The show didn't find its voice until the Dominion made its debut in Season 2, Episode 26. What was essentially the anti-Federation would go on to define the next five seasons of the show through what would be known as the Dominion War. And it was the Changelings, the leaders of the Dominion, who would drive that narrative forward.

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Who Were the Changelings?

Odo fights another Changeling in Star Trek: Deep Space Nine

While their evolutionary process was never discussed, the results were no less impressive. The Changelings were a species whose natural form was a liquid or, to be more precise, a goo. They could take any form and impersonate anyone. That included becoming fog or even energy itself, whatever it took to annoy Quark. The abilities of the Changelings were impressive, to say the least, but that came with problems.

According to the Changelings, they spent several millennia being persecuted by Solids, aka humanoid life forms who can't shape-shift. To defend themselves, the Changelings founded the Dominion and took over a large percentage of the Gamma Quadrant with the brute force of the Jem'Hadar. But they also made their own overtures of exploration by sending 100 young Changelings into space to learn about other cultures. That included Odo, who was raised by Bajorans and became Deep Space Nine's Security Chief.

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What Happened to the Other Explorer Changelings?

Odo talks to Laas

In addition to Odo, only two of the other 100 explorer changelings were accounted for. In Season 5, Episode 12, Odo regained his shape-shifting abilities by absorbing a dying Changeling who was reputedly one of the 100. Then in Season 7, Episode 14, Laas, a Changeling who had been living among Solids, arrived at the station and taught Odo about his potential as a shape-shifter. But beyond them, no other members of the 100 have been accounted for.

Each infant Changeling was imprinted with the overwhelming desire to return home once they reached maturity. But that wasn't supposed to happen until approximately the late 27th Century, meaning their mission still had roughly three centuries to go. Odo returned to the Great Link hundreds of years earlier than he was expected. As such, the remaining 97 infant Changelings are likely still spread across the galaxy. And like Odo and Laas before them, they have no idea that there are more of their kind out there.

Odo's work with the Bajorans and the Federation ultimately led to a truce between the major powers of the Alpha Quadrant and the Dominion. In reality, his mission was more successful than any of his Changeling brethren ever could have dreamed. Still, it's hard not to wonder what impact the remaining 97 Changelings could have on Star Trek, particularly since Discovery is now set centuries after they were scheduled to return home.