The show opens to Will Riker coming aboard DS9 to spend some of his leave time that he has accumulated aboard the Enterprise. He quickly strikes it up with Kira and Sisko being very friendly. After making a few rounds of the Promenade, Riker runs into Kira who promises him a tour of the station. Will suggests going to the Defiant first.
They arrive on the Defiant and look around the bridge. Will attempts to turn on the systems only to find that they are locked out. New security measures for The Defiant...nifty eh?? Not when a couple seconds later Kira releases them without any question and (did anyone else see this coming...?)
"Hi, I'm Tom...not Will"
After faking a warp-core breach, Thomas Riker gains control of The Defiant and takes it into Cardassian Space. Gul Dukat threatens war with the Federation - unless Sisko comes back to help take The Defiant.
The Defiant bursts into Cardassian space destroying some starbases. Eventually, Sisko and the Cardassians realize that all the warships are being drawn away from the Orias system; according to Dukat, this system is uninhabited. Sisko and Dukat send a warship to this "desolate" system "just in case the Defiant shows up." However the observer from the Obsidian Order tells Gul Dukat and Sisko that any warship sent to this sector will be destroyed by the Obsidian Order.
As the Defiant makes its run for the Orias system 3 warships show up from the "empty" system. Where did they come from? Nobody knows because the Obsidian Order isn't allowed to have military equipment. Sisko makes a bargain with Dukat to prevent any destruction of the ship or further death. Riker agrees to the terms and races back to meet the Kraxon where he will surrender.
This all begs the question, why does the Obsidian Order - and for that matter all of the "secret societies" of the Trek Universe have absolutely no one to answer to? They just do whatever they think will "protect" their way of life.