Star Trek: Nemesis
The film opens with an explosion ripping across the surface of Romulus, the planet is decimated and the government eliminated.
The crew of the Enterprise (as well as Lwaxana Troi) are at the wedding of newly promoted Captain Riker and Counselor Troi whilst the Enterprise itself is transporting them to rendezvous with the Titan, Riker's new command.
News reaches the Enterprise about the decimation of Romulus and Picard learns that a militant group, lead by Commander Sela, have risen to power. Admiral Janeway wants the Enterprise to steer clear of the mess and gives orders for the Enterprise to head to a planet known as Kolarus III.
The mission to Kolarus III is routine and the crew suffer from boredom until the Valdore, a Romulan warbird, decloaks in front of the Enterprise and it is revealed that Picard's old foe, Tomalak, is in command of the Romulan ship.
Tomalak asks for parley with Picard and Picard agrees, curious about what Tomalak wants - and what Tomalak wants is Picard (and the Federation's) help to remove Sela from power given that she was found to be responsible for the explosion that decimated Romulus.
Tomalak also believes that Sela has another weapon of the same power to use on Earth - 'a world she hates' - but Janeway denies the Enterprise the right to get involved.
Picard conveys the news to Tomalak who sighs and says that he'll have to fight the good fight on his own. Picard does some soul searching including launching into discussion with Lwaxana - who urges him to get involved.
Data, meanwhile, has been experimenting with reconstructing his android daughter, Lal - the results when he shows the experiment to Beverley and Geordi don't look good, so he returns to work.
Picard orders the Enterprise towards Romulan space after warning the crew that they'll be flying in the face of official orders and he's happy to drop any objectors off on Kolarus.
It is revealed that, despite earlier belief, the alternate Tasha Yar who ended up mothering Sela, is alive on Romulus with her daughter.
Picard meets with Sela, discovers that Tasha is still alive and has to combat sabotage on the Enterprise - eventually chasing Sela's Romulan warbird, the Scimitar, down before it can launch its attack on Earth (Sela has kidnapped Data).
They're joined by the Titan to which Riker and Troi transport to in transit and the final epic battle is the Scimitars vs the combined forces of the Titan, the Enterprise and the Valdore.
Tomalak sacrifices the Valdore to save Earth and the Enterprise after the Titan and Enterprise are practically crippled.
Data sacrifices himself to save the imprisoned Tasha Yar from her daughters ship.