“The Maquis: Part 2” is episode twenty-one of season two of Star Trek: Deep Space Nine.
In the previous episode, “The Maquis: Part 1”, Gul Dukat had been kidnapped by the newly announced group calling themselves the Maquis, who are opposed to the Cardassians. Sisko discovered that his friend, and a fellow Starfleet commander, Cal Hudson, was also working with them, although this is a secret he keeps from Starfleet for the moment, hoping that Cal will return to the fold.
The Cardassian Central Command, instead of going after Dukat, essentially throw him under the bus, blaming him for shipping weapons to Cardassians in the demilitarised zone. Sisko therefore decides to rescue Dukat himself – he wants to keep Dukat alive simply because the Cardassians want him dead, probably as a scapegoat.
With Dukat, Sisko has to then track down the Maquis, and the arms shipments being supplied by the Cardassians, and stop a Maquis raid before it takes place and risks destroying the treaty between the Cardassians and the Federation.