WARNING: This article contains SPOILERS for Star Trek: Picard season 3, episode 4, "No Win Scenario."Star Trek: Picard season 3 has brought back the Changeling villains from Star Trek: Deep Space Nine, and they've undergone some significant changes in the years since the Dominion War ended. As they're plotting a revenge attack against the Federation, it makes perfect sense for the Changelings to adapt to cheat the security precautions introduced during the Dominion War. Picard has revealed that at least one Changeling has infiltrated Starfleet, when it impersonated Ensign Foster (Chad Lindberg) aboard the USS Titan-A.
It remains to be seen if there are more Changeling infiltrators within Starfleet, but at this stage it seems inevitable that the institution has been compromised. During Star Trek: Deep Space Nine's Dominion War arc, the Changelings impersonated several DS9 characters to gain a tactical advantage against the Federation. In Star Trek: Picard season 3, it appears that the Changelings are up to their old tricks, but with significant updates to their methods of operation. Here's every significant change made to the Changelings in Picard season 3.
