“Paradise Lost” is episode twelve of season four of “Star Trek: Deep Space Nine.
In the previous episode, “Homefront”, Earth had been put under martial law for fear of a Dominion attack after the planet’s power relays were taken down. A shapeshifter had been discovered at Starfleet Headquarters itself.
However, Sisko starts to question what is going on. He discovers that Red Squad – an elite and, as it turns out, highly secretive, group of cadets that Nog had told him about – had been active just before the power relays were taken out. Sisko can’t see how the Changelings would have been able to take out all the relays so easily.
It turns out that Sisko is right to question what is going on. It seems that this is all part of a plot, one founded with the best of intentions – to do what it takes to eliminate the Dominion threat. Sisko has to try and find enough evidence when even his own people are turning against him.