"Once More Unto the Breach" is an episode from the seventh season of Star Trek: Deep Space Nine. The title is taken from one of the more famous speeches in Shakespeare's play Henry V. The episode has an average rating of 4.3/5 on the official Star Trek website (as of August 20th, 2007).
Meanwhile, Martok tells Benjamin Sisko his plan to take five cloaked Birds of Prey deep into Cardassian space to quickly strike at several important Dominion targets and then disengage. Sisko recalls from Earth history that this plan sounds remarkably like a cavalry charge. He explains that in ancient battles men on horseback would be strong enough to disrupt activities behind enemy lines but still be too fast to get caught. He approves the plan and helps with the preparations, including having a number of starships on standby in case the remaining Klingon ships bring company home with them.
Worf tries to talk to Martok about Kor, but Martok won't listen. At length Martok relents and explains why he doesn't want to give Kor a ship. As a young man, Martok aspired to be an officer, but the decision rested with Kor, who rejected Martok's application. Even though Martok eventually overcame this obstacle, he's still not inclined to help Kor now.
Despite not being quite what Kor wanted, Worf appoints him third officer on the Ch'tang and urges him to stay out of Martok's way. This proves difficult as Kor is treated as a living legend by the crew of the Ch'tang as he is a famous Dahar master and thus a large source of attention. In the mess hall, the crew listens entranced as Kor tells the story of his victory against the Federation at Caleb IV.
General Martok explains the plan of attack for their strike against the Cardassian starbase at Trelka V. Two of the Birds of Prey will decloak and make a single strafing run and then head out of the system. Soon after when their repair crews begin to assess the damage, the rest of the squadron will continue the assault. Once they arrive the attack proceeds perfectly even though one of the ships is destroyed by a Cardassian warship as it is retreating. During the second half of the skirmish, both Martok and Worf are knocked unconscious. Kor takes command, but with a sudden display of senility, orders a boarding party despite the starbase's garrison of thousands of soldiers. Kor rants that "The Federation will rue the day they dared to challenge the might of the Klingon Empire! We will take Caleb IV, and raise our banner over the smoking ruins of their own post!" The bridge crew is puzzled and are unsure of what to do. Martok realizes what's going on and takes out his knife to throw it at Kor in an attempt to kill him. Worf starts to come to and in a quick sequence of events catches Martok's knife in midair, forcefully knocks Kor to the ground, and orders them to retreat.
In the mess hall, the crew mocks Kor mercilessly. Martok does too, but later admits he gets no satisfaction from it. At that point, long range sensors show that 10 Jem'Hadar ships are tracking the Klingons even though they are cloaked. At the current rate, the Jem'Hadar will catch up to them before they reach the rendezvous with the Federation ships. The only way to shake them, Worf says, is by sacrificing one ship to stay behind and disable the warp drives of each Jem'Hadar ship. Considering there are only four ships left in their group, and the fact that one of the other captains died while the remaining one is too inexperienced, and the third ship is too damaged, Worf himself volunteers to command one of the other ships in the venture. Knowing that survival is unlikely, it is decided to transport everyone off the ship they are to use so as not to sacrifice the entire crew. A small crew that will carry out the plan along with Worf will be the only ones on board.
Kor hears of the plan and realizes what he must do in order to die a warrior's death since he has no chance for another command now. On his way to the transporter, Kor ambushes Worf with a hypospray and takes his place. The crew watch their sensors as Kor successfully disables all of the Jem'Hadar ships and then engages them. The last bit of sensor data they receive before moving out of range is Kor's ship taking much return fire as it maneuvers rapidly in order to do as much damage as possible. It is reported that their entire formation has collapsed, therefore the enemy force will be delayed long enough for them to reach the Federation ships. The episode closes with the crew singing of Kor's victory over the superior enemy forces.