A torpedo inflicts damage to the USS Enterprise, NCC-1701-A
The Enterprise entered the Khitomer Sector at approximately 09:37:00 hours and Kirk ordered the helm to slow to impulse for Khitomer orbit. Commander Uhura informed Kirk that she couldn’t hear General Chang's Bird-of-Prey’s engine, which must have meant they were rigged for silent running.
When the Enterprise was within approximately 40 seconds of transporter range, General Chang hailed the vessel, taunting Kirk with his own ship’s invisibility. The first shot was fired by the Bird-Of-Prey, the photon torpedo struck the ventral-port side of the Enterprise’s saucer section. Kirk immediately ordered the ship to reverse at half impulse power, prompting Chang to wonder what they were doing. When Kirk asked himself a similar question, Spock responded that Chang was likely trying to ascertain whether his ship was detected. After a moment of indecision on either side, Chang ordered a second torpedo that presumably struck the dorsal-starboard side of the vessel. Meanwhile, a desperate Sulu ordered the Excelsior flown to her limits to help Enterprise.
The Enterprise continued orbiting the planet, as Kirk’s legendary tactical skills were of no use against an invisible enemy. The next shot fired struck the aft-port of Enterprise hull near the nacelle pylon, causing the bridge to erupt with destroyed circuitry; among the destroyed circuits was the ship’s auxiliary power. After recovering from the last blow, Spock noted that the Bird-Of-Prey would still release ionized gas under impulse power, to which Uhura responded that the ship was carrying equipment to catalog gaseous anomalies. As Spock asked Dr. McCoy to assist him in the modification of a torpedo, another shot rocked the Enterprise and Kirk ordered the ship hard to starboard.
It would seem that Chang had intentionally let the Enterprise in front of his vessel, as the next shot fired also came from the rear, though his aim had tapered a bit, as the shot would appear to glance off the dorsal-port side of the saucer section. The shot caused major distress in the engineering decks and Scotty was quick to note that the torpedoes were packing ‘quite a wallop’ and that the shields, specifically the forward ones, were weakening. The shot also caused major damage to the hull, which from the exterior was visually spewing bolts of electricity.
Fortunately for the Enterprise, the Excelsior entered the sector and raised its shields just after the previous torpedo had been fired. Chang was intrigued by the new enemy and targeted Excelsior’s saucer section; the torpedo struck the ventral-starboard side of the vessel, causing a major shift in the inertial dampening field, strong enough to send Sulu and several Excelsior crewmembers literally flying across the bridge. The torpedo, however, did not do major structural damage to the ship itself.
The Enterprise was struck again and the torpedo caused the shields to almost completely collapse. With the shields weakened, Chang took advantage and fired a torpedo from underneath the Enterprise and again struck the ventral-port side of the saucer section, only this time the torpedo punctured the hull and exited the other side; destroying, among other things, the Enterprises’ dining room.
At this point, McCoy and Spock were in the forward torpedo tube, lifting the dorsal access port of the torpedo and preparing to connect the echobars; they then converted circuit ‘A’ to sensor status. After removing a circuit board from the torpedo, they inserted another one, the ‘plate’, and the torpedo’s newly conceived tracking device came online. The final step, as Kirk screamed at them for the torpedo, was to insert the torpedo’s key. Once that was done, McCoy informed the Captain that the torpedo was ready.
Kirk appeared to take a great deal of satisfaction in finally ordering the torpedo to be fired, to which Commander Chekov immediately responded and the torpedo was away. The sound of the tracking device was audible to the crew of the Bird-Of-Prey as they stood in disbelief; undoubtedly the power required to fire weapons and remain cloaked was too much to have their shields raised, and their only other option perhaps an attempt to decloak and raise shields. Chang made no effort to stop the blast, instead asking one last time, “To be, or not to be?”
Though tracking the impulse signature, the torpedo appeared to strike the dorsal-fore of the Bird-Of-Prey, temporarily making it visible. Upon the impact, Sulu ordered the Excelsior to target the explosion and fire as Kirk simplified his order and just insisted that the Enterprise fire. Each vessel fired no less than three torpedoes apiece, completely destroying the Bird-Of-Prey.