Star Trek The Next Generation: Redemption

The episode begins with the Enterprise en route to Qo'noS so that Picard can attend the installation of Gowron as Leader of the Klingon High Council (see: "Reunion"). Unexpectedly, the Enterprise is intercepted by a Klingon vessel, the Bortas, which is to escort the Enterprise to its destination. Commanding the escort vessel is Gowron, who informs Picard of a conflict — one that could throw the Klingon Empire into a civil war — between himself and the House of Duras for the position of Leader of the High Council.
In a bid to restore his family honor Worf requests a leave of absence which Picard grants. He seeks out his brother Kurn who is Captain of a Bird-of-Prey. Kurn tells Worf he opposes Gowron and has the support of several squadon commanders within the Klingon fleet. In addition he informs Worf that most of the fleet has not yet chosen a banner to follow, be it either Gowron or the House of Duras. However Worf convinces him that remaining with Gowron is the best chance to restore their family honor. Kurn reluctantly agrees but must speak to his allies.
As Gowron is about to be installed as Leader of the Klingon High Council the Duras sisters interrupt with a challenge. With them is Duras' illegitimate son Toral who has the lineage necessary to challenge Gowron's leadership. The council votes to accept the challenge and assigns the position of "Arbiter of Succession" to Picard; because he must be neutral in order to interpret the law and see that the rightful person acquires the position. After the sisters meet with a Romulan officer and a mysterious woman, they invite Picard to their home to assure him choosing Toral would be in the Federation's best interest. Picard is suspicious of possible motives and alliances the Duras sisters made and the next day rejects Toral as a candidate at the High Council, stating that there is no precedent in Klingon law for allowing an inexperienced young person to assume leadership. However, many Council members indicate their support for Toral's challenge.
Worf meets with Gowron on the IKS Bortas and offers the support of several Klingon warship squadrons (led by Kurn) to Gowron in exchange for restoring his family's honor. Gowron rejects the offer saying it is not enough. Instead he attempts to enlist Worf's aid in acquiring Starfleet assistance but Worf rejects the idea; he's already been warned by Picard that the Federation cannot be further involved. At that moment the Bortas is attacked by two Birds-of-Prey. The ship suffers heavy damage, including the loss of their weapons and warp-drive. Gowron orders the transmission of a distress call requesting assistance from any loyal ships. On the Enterprise the crew pick up the distress call but when Riker questions Picard's decision not to intervene he counters that if they go to the aid of the Bortas they will be dragging the Federation into a Klingon civil war. He then orders the ship out of the combat area.
On the Bortas, Worf manages to get the ship's disruptors online. But instead of opening fire they try to lure the attacking ships in, knowing that they will try to board and finish off the crew. Sure enough the Birds-of-Prey drop their shields to allow transport and Worf opens fire, obliterating one of the attacking ships. However when he fires on the second ship the disruptor blast impacts on the ship's shields. The remaining Bird-of-Prey then returns fire knocking the Bortas' weapons offline and causing life support to fail. Just as all seems lost another Bird-of-Prey arrives and fires on the first forcing it to flee. The arriving ship is revealed to be Kurn's who, along with his crew, has "come to defend the Empire and follow the banner of Gowron."
With the fighting over, temporarily, the Enterprise returns to Qo'noS and Picard completes the rite of succession installing Gowron as Leader of the High Council. As a mark of thanks for their actions Gowron restores Worf's family honor. Back on the Enterprise Gowron informs Picard that the Duras sisters are assembling a fleet and, along with Worf, asks for Federation assistance in fighting these "enemies of the empire". Riker points out that these "enemies" are Klingons but Gowron counters that by right and tradition he is the sole leader and that all who oppose him are traitors. Picard reiterates that the Federation cannot get involved in Klingon internal affairs and must therefore decline Gowron's request. This leaves Worf in the difficult position of choosing between Starfleet or returning to help his people. Worf resigns his Starfleet commission to join the Klingon Fleet as civil war threatens to unravel the Klingon Empire.
Back at the home of the Duras sisters, the Romulan officer Movar announces that Picard has rejected Gowron's plea for help. When Toral triumphantly declares Picard as a coward, he is silenced by the female Romulan. Stepping out into the light, the Romulan has blonde hair and looks and sounds a lot like Tasha Yar. She declares to everyone, "we should not discount Jean-Luc Picard just yet. He is human and humans have a way of showing up when you least expect them."
Although Picard refuses to involve Starfleet in Klingon affairs he fears the Romulans will try to take advantage of the situation, citing history of previous collaboration between the Romulans and the House of Duras. He sums up the situation to Fleet Admiral Chantele saying the Romulans are prepared to take enormous risks to gain any advantage over the Federation - "can we seriously expect that with the future of the Klingon Empire in the balance they are content to just sit back and watch?"
After convincing Starfleet of the threat and devising a way to detect cloaked Romulan ships, Picard is put in charge of a fleet which will create a blockade along the Klingon-Romulan border against Romulan convoys supplying the Duras family. Because of a manpower shortage amongst the ships available, various Enterprise officers must be put in temporary positions on key ships to coordinate fleet preparations and deployment; Riker and La Forge are assigned as temporary captain and first officer of the USS Excalibur. Data asks Picard why he was not selected to command one of the ships. After all, the android points out, he is the third most senior officer among the Enterprise staff (and, given his twenty-six years in service, probably the most experienced officer on board save Picard himself). Somewhat reluctantly, Picard gives Data his own command, the USS Sutherland. The fleet is then quickly dispatched to the Romulan-Klingon border.
On the Sutherland, Data is confronted with the prejudice of his crew which is voiced by his executive officer, Commander Christopher Hobson. They are not confident an artificial life-form can be a commanding officer. Data notes his objections but denies Hobson's request for a transfer.
Meanwhile the Duras sisters meet again with Commander Sela who looks very similar to the late Starfleet officer Tasha Yar; but the sisters are troubled by the possible interference of Picard's fleet in their plans to take over the Empire. Sela sends word back to Romulus for all available ships to be at the border in 2 days. Meanwhile, following heavy combat, Worf, Kurn and the crew of Kurn's ship are resting, Klingon-style, while their ship is repaired. This consists of mostly drinking and fighting. However the capital city is deemed neutral ground so when Worf has an encounter with a Commander from the Duras fleet who has insulted him, Kurn prevents him from starting anything citing, "Larg's men are all around us, as are mine." Later following an argument with Kurn in which he storms off, Worf is attacked and abducted from the 'establishment' by unknown attackers.
With the Federation fleet in position on the Klingon-Romulan border a detection network is established between the ships to uncover any cloaked Romulan convoys supplying Duras. Commander Sela orders her scientists to work on a way to disable the network, but to confuse Picard she contacts the Enterprise and reveals her identity as she warns the fleet to withdraw. Initially concluding Sela's existence is a Romulan trick Picard is visited by Guinan who tells him Sela is not only telling the truth, but that he was somehow responsible for her conception by sending Tasha on the Enterprise-C 23 years in the past despite her death on the Enterprise-D years ago.
To get to the bottom of things Picard invites Sela to a meeting on the Enterprise, to which she agrees. Once on board Picard avoids Sela's questions and asks about her background. Sela quickly deduces that what Picard really wants to know is how she is the daughter of Tasha Yar. Her story corroborates Guinan's recollection and Picard concludes that, however strange, Sela is indeed Tasha's daughter. Without making any headway with Picard, Sela gives him a fourteen-hour deadline to either retreat or be attacked.
At the same time Worf's kidnappers deliver him to the Duras sisters, who try to bribe Worf to join them by marrying the young attractive B'Etor and be the power behind Toral in the High Council. Worf rejects their offer since their methods and cooperation with the Romulans is without honor. Sela overhearing Worf's decision orders him taken away for "questioning", promising to return him later.
Picard becomes concerned that as time passes and the deadline nears the fleet may have to square off against the Romulans which could very well widen the war. He contacts Gowron and asks that he launch a full offensive on the Duras fleet; forcing the sisters to call for help and the Romulan convoy to take action.
On Sela's Warbird word comes in of Gowron's all out assault and that the Duras are running low on supplies and nearing defeat. On the plus side the Romulans believe they have a way to disrupt the Starfleet detection grid. Suddenly they note that one of Picard's ships is withdrawing from the blockade, apparently suffering problems with their warp drive. This opens a hole in the network but Sela suspects it's too good to be true, and instead decides to disrupt the network. A beam aimed at one of the ships should disable the detection grid in a localized area, and Sela chooses Data's ship to be the target.
The Romulans use the beam and the network begins to fail around the Sutherland. Picard orders the fleet to retreat and redeploy the grid further into Klingon space but Data, after doing some quick research, orders his ship to stay behind. Data theorises that the beam used by the Romulans may have made their own ships detectable. On the Enterprise Chief O'Brien, who is serving at Tactical, notes that the Sutherland is not withdrawing with the rest of the fleet. Picards orders Data to explain why he isn't complying with the retreat order but Data replies asking Picard to 'stand by'. After scanning the area around their ship, several anomalies are detected. Data orders low yield photon torpedoes fired at the anomalies but Hobson protests stating they have no idea what they are and that even if they are Warbirds, the low yield torpedoes won't do any damage. Data responds with a calculated expression of anger to force his compliance.
The photons uncover three cloaked Romulan ships and Sela, realising the game is up, orders a retreat. Without the convoy the Duras are losing quickly to Gowron's attack. Worf is returned to the Duras sisters but B'Etor rejects him, and just as Worf is to be executed the room they are in is hit by weapons fire. Worf seizes the opportunity and attacks his Romulan guard. Seeing that Worf is about to emerge victorious the sisters escape via transporter, leaving Toral behind. Kurn and several warriors arrive and take Toral into custody with Kurn sneering to Toral that "Gowron is looking forward to meeting you".
With the civil war ended Picard orders the rest of the fleet to return to Federation space while they return to Qo'noS. Data reports to Picard in his ready room, telling the captain he is prepared to be punished for disobeying a direct order; he does not believe it ethical to defend himself by saying that the ends justify the means. Picard responds that Starfleet wants officers who can think and act independently, implicitly admitting that he was wrong for not giving Data his own command earlier. He dismisses Data with a smile and a "Nicely done."
In the High Council chambers Picard gives Gowron a debriefing and data on the encounter with the Romulans. With Gowron's position on the High Council secure he thanks Picard and rewards Worf with Toral's life. Worf is given the honor of killing the son of the Duras family, which disgraced his family and sent Worf into exile to cover up Duras' betrayal of the settlers at Khitomer. (see: Sins of the Father) Realizing it does not agree with his personal philosophy and, reflecting on the numerous disagreements he had on the "Klingon way", Worf spares Toral's life and requests permission to return to the Enterprise. Picard happily accepts and Worf's brother Kurn is left in the High Council to rebuild the family honor.