Trama

The Enterprise is diverted to the Romulan homeworld Romulus, supposedly because they want to negotiate a peace treaty. Captain Picard and his crew discover a serious threat to the Federation once Praetor Shinzon plans to attack Earth.

After a joyous wedding between William Riker and Deanna Troi, Captain Picard and the Enterprise crew stumble upon a positronic signature which results in a prototype version of the android Data. Then the Enterprise is invited to Romulus to negotiate a peace treaty with the Romulans by their new leader, Praetor Shinzon. However, Shinzon is revealed to be a clone of Picard who was raised on Remus, a slave planet to the Romulans. Later on, Picard discovers that this peace treaty was nothing more than a set-up on account of the fact that Shinzon needs Picard in order to survive. But little do the Enterprise crew know that Shinzon also plans to do away with the Federation by unleashing a weapon that could destroy a whole planet.—Blazer346

On their way to William Riker and Deanna Troi's honeymoon on Betazed, the Enterprise heads near the Romulan Neutral Zone, and picks up a prototype version of the android Data. Immediately, they are diverted to Romulus, where the new ruler, Praetor Shinzon, a human cloned from Captain Picard who lives on the slave planet Remus, appears to want peace with the Federation. But then the crew detects a break-in on their computer systems, and Picard is captured by the Remans because Shinzon needs him as his only matching supplier of genetic material. Picard and the Enterprise crew escape, only to find themselves battling Shinzon's completely cloaked Warbird, who goes after the complete destruction of Earth.—42/103

On Romulus, the Romulan military offers the Imperial Senate plans to join forces with the Reman military and invade the Federation, but Praetor Hiren (Alan Dale) refuses to cooperate. A green thalaron radiation mist is released by a small device into the room, and everyone is disintegrated. Meanwhile, the crew of the USS Enterprise-E prepares to bid farewell to longtime first officer Commander William Riker (Jonathan Frakes) and Counselor Deanna Troi (Marina Sirtis), who are soon to be married on Betazed. The android officer Data serenades the newly married couple with rendition of Irving Berlin's song "Blue Skies" at a reception.

On route, the crew discover a positronic energy reading on a planet in the Kolaran system near the Romulan Neutral Zone. Captain Jean-Luc Picard (Patrick Stewart), Lieutenant Commander Worf (Michael Dorn), and Lieutenant Commander Data (Brent Spiner) land on Kolarus III and discover the remnants of an android resembling Data. When the android is reassembled he reveals its name is B-4 (Brent Spiner), and the crew deduce him to be a less-advanced earlier version of Data. Vice Admiral Kathryn Janeway (Kate Mulgrew) surprises Picard when she orders the crew to conduct a diplomatic mission to Romulus. Janeway informs Picard that the Romulan government has undergone a military coup and is now controlled by a Reman named Shinzon (Tom Hardy), saying he wants peace with the Federation and to bring freedom to Remus.

This is a surprising development as the Romulans had regarded Remans as second-class citizens in Romulan society used principally as slave labor and cannon fodder, due to their long history of prejudice. Upon their arrival on Romulus, the crew learns that Shinzon is actually a clone of Picard, a remnant of a secret experiment conducted by the Romulans to take Picard's place in Starfleet as a spy; however, he and the project were abandoned after a political change in the Romulan government left him cast away to Remus as a slave. It is there that he meets his Reman brothers and brings about his rise to power. It was also on Remus where Shinzon constructed his flagship, a heavily armed warship named the Scimitar, with completely undetectable cloaking devices, an arsenal of weapons, and virtually impregnable shields.

Though the diplomatic mission seems to go smoothly, the crew discovers that the Scimitar is emitting low levels of extremely dangerous Thalaron radiation, the same substance used to assassinate the Romulan Senate as seen in the film's beginning. Several unauthorized computer accesses take place aboard the Enterprise, and Counselor Troi is mentally attacked by Shinzon while she is making love to Commander Riker. Picard is suddenly captured by Shinzon and is informed that he is slowly dying from the accelerated aging from his cloning process, and thus needs Picard's blood to live. Shinzon also transports B-4 aboard the Scimitar, revealing that Shinzon was behind the placing of B-4 on Kolarus III in order to lure Picard to Romulus. However, B-4 reveals himself to actually be Data - he rescues Picard, and they make their escape back to the Enterprise.

Realizing that the Scimitar is a weaponized thalaron emitter with enough power to eradicate all life forms in a fleet of ships as well as an entire planet, Data deduces that Shinzon is using the warship to conquer the Federation and destroy Earth. The Enterprise races back towards Federation space, but is soon ambushed by the Scimitar, disabling the Enterprise's warp drive in the process in her first volley of photon torpedoes. In the ensuing assault, the Enterprise is outmatched in the Bassen Rift, a region which prevents subspace communications. Two Romulan Warbirds arrive and assist in the assault, but Shinzon destroys one Warbird and disables the other. Refocusing his attention on Picard, Shinzon damages the Enterprise to a significant degree.

Refusing to surrender, Picard uses his heavily damaged ship to ram the Scimitar, but only succeeds in slightly damaging the other ship. Picard even tries to initiate the Enterprise's self-destruct sequence, but finds it disabled from the attack. Meanwhile, Shinzon initializes the Scimitar's thalaron weapon in a desperate attempt to take down the Enterprise with him. Picard boards the vessel alone and faces Shinzon, and leaves Data in command. Unable to stop the weapon from activating, Picard kills Shinzon by impaling him through the abdomen with part of a metallic support strut. Data arrives with a single-use personal transporter, using it to quickly beam the captain back to the Enterprise before sacrificing himself to destroy the ship, shutting down the weapon in the process.

While the severely damaged Enterprise is under repair in a spacedock in near-Earth orbit, Picard bids farewell to newly promoted Captain Riker who is off to command the USS Titan, to begin a true peace negotiation mission with Romulus. Picard then meets with android B-4, whereupon he learns that Data had succeeded in copying the engrams of his neural net into B-4's positronic matrix not long before his death. Though B-4 does not behave as Data, Picard is assured that he will become like his friend in time as he walks down the corridor for the bridge.