- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
Grand Nagus Zek, the ruler of the Ferengi empire and paramour to Quark and Rom's mother, disappears while on a business trip to the mirror universe. Ezri's counterpart from that universe delivers word that Zek is a prisoner of the evil Alliance and will be killed unless Quark can secure a cloaking device, which renders a ship invisible. Quark and Rom steal one from a Klingon vessel, then accompany Ezri back to the mirror universe to retrieve Zek
Once there, Rom, Ezri and Quark are held captive by Bashir and O'Brien's mirror universe doubles, who are rebels in the resistance movement against the Alliance. The two intercept the cloaking device before it falls into the hands of the enemy, but later, a mirror universe Ferengi named Brunt retrieves the device and frees Quark and his fellow captives.
Quark, Ezri, Rom and Brunt bring the cloaking device to the Alliance leader — Worf's counterpart — who rules from his Klingon flagship. With possession of the device, the Alliance will soon be able to crush the rebellion. Unfortunately, Worf, known in this universe by the title of Regent, not only refuses to turn Zek over in exchange for the coveted mechanism, he throws Quark and Rom into Zek's prison cell. The mercenary Ezri has betrayed them.
Brunt tries to convince Ezri to lobby the Intendent, Kira's mirror universe double, for Quark and Rom's release. The Intendent then kills Brunt, branding him a traitor. Rom is called in to activate the cloaking device, and Ezri hints that compliance is the key to Quark and Rom's survival. Yet as soon as the device is operational, the Regent orders his enforcer Garak to kill the prisoners.
Meanwhile, with Bashir and O'Brien in pursuit of Rom and Quark, the Regent orders an attack on the rebels' ship, which the cloaked Klingon vessel has been trailing. But once the assault begins, Worf's ship loses power: Rom sabotaged its primary systems when he activated the cloaking device. Following her conscience, Ezri prevents Garak from killing Quark and Rom, while O'Brien and Bashir force the Regent to surrender. Although Ezri allows the Intendent to escape, Quark and Rom are assured a safe return home with Zek.