Defiant: Riker's evil clone steals the Defiant.
DS9 is having resource issues, making Kira go batshit. Bashir decides she needs some time off, and relives her of duty. And forces her to spend time at Quark's to relax. Fortunately(?) at this point Riker turns up. Which reminds me: when are Prime going to resume showing Next Generation?
Riker meets with Sisko, while in Ops, Dax and Kira chat about him. I thought Kira was relieved of duty. What's she doing in Ops? Dax observes that Kira seems to have taken a liking to the commander.
Later on, Riker "accidentally" runs into Kira on the Promenade, and she takes him on a tour of the station, including the Defiant. They encounter O'Brien, who Riker is hostile towards. Note, Prime, this is what happens when you play stuff out of order.
Once Kira releases the lockdown on the Defiant bridge, Riker shoots her and beams in a couple of pals. He reports to Ops that the Defiant's got an imminent core breach, and, once the docking clamps are disengaged, sods off with the ship towards the badlands. Also, Riker takes off a couple of strips of fake hair to reveal... A BEARD OF EVIL! Dun dun duuuuuuun!
Yes, it's Riker's evil clone, from an episode of TNG which Prime haven't played yet.
Sisko and Odo brief Gul Dukat on Evil!Riker's backstory and reveal that Riker's now a member of the Marquis and has stolen the Defiant. Dukat says the Cardassian high command will likely respond by sending a fleet to wipe out the Marquis, which may lead to war with the Federation. Sisko and Dukat go to Cardassia Prime to co-ordinate the search and encounter Korinas of the Obsidian Order. Sisko admits the Defiant has a cloak (the Obsidian Order, of course, already knew) and says there may be a way to penetrate it.
The Marquis use a decoy ship to draw ships off the border so they can attack a Cardassian station. Those computer graphics on the Cardassian screens look highly unrealistic. :P Korinas is impressed with Sisko's tactical advice.
Meanwhile, Kira sabotages the power grid and knocks out the cloaking device, forcing the ship to hide in a nebula. Riker is not very impressed.
Dukat grumbles because he promised to take his son to Cardassian Disneyland for his birthday.
Riker sets course for a minor shipyard, and reveals to Kira that there's a rumour that a group of renegade Cardassians are building a fleet of ships. Kira tells him he's a crap terrorist.
Sisko and Dukat analyse the attacks, and discover that the Defiants been drawing Cardassian ships away from a remote system. They decide to send a warship there, but Korinas says the system is under Obsidian Order control and no one's allowed to go there.
The Defiant makes a run for the Orias System, and Cardassian ships set out in pursuit. Three more warships appear in the Orias System, which excites Dukat because they must be Obsidian Order ships, and the Order isn't supposed to have any.
Kira bitches at Evil Riker that this is all jealousy over his more successful self on the Enterprise.
Sisko haggles with Dukat over who gets what when they capture the Defiant. The end decision is that the Cardassians get Riker and some Defiant sensor logs, and the Federation gets the Defiant and other Marquis. They contact the Defiant and give their terms.
Kira talks Riker into surrendering, and he flies the Defiant to on of Dukat's ships. After he snogs her and beams onto the Cardassian ship, Kira takes command of the Defiant and sets course for the Federation.