The Menace (Star Trek/Star Wars Crossover)

Searching for survivors from a freighter that's been missing for seven years, the USS Enterprise-D, under the command of Captain Jean-Luc Picard, visits the matriarchal planet Angel I and gets a frosty reception from its female leaders. Commander Riker especially seems out of place as Lieutenant Tasha Yar and Counselor Troi handle the diplomacy, but he finds a more personal way to gain leader Beata's trust.

Survivors are found, but they refuse to return. They have taken wives from among outcasts on the planet who don't like the status quo: dominant women and submissive men.

Back aboard Enterprise, crises break out as a virus from the holodeck file ravages the ship and Starfleet wants a response to a reported Romulan incursion near the Neutral Zone.

The renegade women are discovered and sentenced to death along with their Federation mates as enemies of society. Riker intercedes and violates the Prime Directive by beaming the outcasts aboard the Enterprise, despite protests by Dr. Beverly Crusher because the epidemic is in full swing.

The Guardian Warriors come aboard the Enterprise-D and, with the help of Dr. Crusher, find a cure for the virus. The Enterprise-D then warps out to counter the Romulan activity.

After the Enterprise counters the Romulan activity, she returns to Earth, capital of the Federation, where Commander Riker is demoted to Lieutenant and ordered to return to Starfleet Academy. But Good Vader, feeling that Riker deserves a second chance, successfully lobbies Starfleet to allow Riker to be assigned as navigator aboard the USS Excelsior under the command of Captain Hikaru Sulu.

The evil Emperor Bad Vader orders his Imperial forces to bomb a secret Section 31 installation in London. After the bombing, Captain Sulu and Lieutenant Riker attend a meeting at Starfleet Headquarters in San Francisco to discuss the bombing and the manhunt for Bad Vader and his Imperial forces. The meeting is attacked by one of Bad Vader's Imperial fighter squadrons and some Starfleet officers are killed, but Riker destroys the fighter squadron.

In the aftermath, Riker is promoted to Commander and is reinstated as first officer of the Enterprise-D under the command of Captain Picard. Picard receives orders from Starfleet to hunt down the Romulans, who are allies of Bad Vader. 210 prototype photon torpedoes are delivered to the Enterprise-D and Good Vader and Starfleet order Picard to fire them at the Romulan base. Lieutenant Commander Crystal, the Enterprise-D's chief engineer, resigns and Jasmine is promoted to Lieutenant Commander and is made the Enterprise-D's new chief engineer. Luke Skywalker also joins the Enterprise-D's crew. The Enterprise-D then warps to Romulus to destroy the Romulan base.

The Enterprise-D arrives at Romulus and Riker, Data, Geordi, and Luke take a shuttlecraft to Romulus. The shuttle is intercepted by the Romulans and is forced to land. The Romulans then prepare to kill Riker, Data, Geordi, and Luke. Suddenly, Darth Vader, Luke's father, arrives and helps Luke and the 3 Enterprise officers kill the Romulans. The Enterprise-D then destroys the Romulan base with one of the prototype torpedoes. Luke, Riker, Data, Geordi, and Vader then return to the Enterprise-D, where Vader is introduced to the rest of the crew. Vader then reveals that Emperor Palpatine is a menace to both universes and must be destroyed. The Enterprise-D then opens a vortex and warps to Endor in the Star Wars universe to destroy the Death Star II and kill Palpatine.

The Enterprise-D and the combined Federation/Allied Galactic Fleet arrive at Endor and engage the enemy fleet. Data transmits the code and the Death Star II's shield is lowered. Luke and Vader beam to the Death Star II and confront Emperor Palpatine, who promptly uses blue Force lightning to attack Luke. Luke begs Vader to help him. Vader casts the Emperor down a reactor shaft to his death, but is mortally wounded by the Emperor's lightning. At his request, Luke removes Anakin's mask to look into the eyes of the pale, withered man that is his father. Having seen his son with his own eyes for the first, last and only time, Anakin dies, finally at peace.

The Federation/Allied Galactic Fleet destroys the Death Star II, but Luke escapes in an Imperial shuttle with his father's body. On Endor, Leia reveals to Han that Luke is her brother, and they share a kiss. That evening, Luke goes to Endor and cremates his father's armor on a funeral pyre. Both universes celebrates the fall of the Empire. During the Allied Galactic Forces' own celebration on Endor, Luke catches sight of the spiritual figures of Obi-Wan, Yoda, and his father, who watch over them with pride.