Memento Mori

The Enterprise attempts to deliver a nuclear-powered air filter to a Federation colony, but finds many of the colonists dead. Security chief La'An Noonien-Singh helps evacuate the survivors and recognizes the situation as a Gorn trap; she was the only survivor of a Gorn attack in her childhood. A Gorn ship attacks and does significant damage to the Enterprise. M'Benga and nurse Christine Chapel resort to 21st-century medicine to treat the wounded when their equipment goes offline. The crew lure the Gorn ship into the atmosphere of a brown dwarf near a black hole, where both ships' sensors and shields are useless. Spock figures out a way to track the Gorn ship and they destroy it, but three more Gorn ships arrive. One is crushed by the pressure of the brown dwarf's atmosphere.

Summary from Wikipedia, CC BY-SA 4.0.