The IKS Pak'tu was a Klingon Bird-of-Prey under the command of Captain Kardok, who served The X. It was destroyed in 2381 during a battle with the USS Enterprise-E and all aboard were presumably killed.
On stardate 57189.4, the USS Enterprise-E had been sent on confidential orders to seek out a secret society that wished harm upon the Federation. The Pak'tu, under the command of Kardok, was lying in wait for an unsuspecting vessel, and the Enterprise fell into their trap. Kardok sent a boarding party to try to take control of Enterprise's engineering section, but it was unsuccessful. The Klingons were forced to retreat after multiple skirmishes left the Pak'tu nearly crippled. Kardok left Captain Jean-Luc Picard with a warning that they would return, and the Pak'tu left the system with haste.
On stardate 57823.6, the Enterprise began a search for the Pak'tu. They located its warp trail and began tracking it down. After several hours, the Pak'tu decloaked and opened fire on the Enterprise. Both ships exchanged fire until the Pak'tu took heavy damage and retreated once more. Kardok, knowing the Enterprise had also sustained much damage, brought a boarding party with him onto the bridge of the Enterprise. They nearly took the ship, but were foiled by the android, B-4, who drove them back to the Pak'tu. Captain Picard ordered his tactical officer, Worf, to disable the Pak'tu, but it was destroyed in the process, the damage inflicted already being too much for the ship to handle. All aboard were presumed killed.
The Pak'tu was commanded by Kardok, a confident and devious Klingon captain. He ordered multiple direct assaults on the USS Enterprise-E, causing both ships to suffer major damage. Kardok sent boarding parties onto the Enterprise on two separate occasions (one including himself), but both were unsuccessful. In the end, he was driven back to the Pak'tu in disgrace, and the ship ended up being destroyed. Whether he or anyone else on board survived remained unknown.
Another officer of the Pak'tu, Telnok, led one of the boarding parties sent by Kardok. His team failed to take the engineering section of the Enterprise and was forced to retreat back to the Pak'tu. Telnok later was killed during a battle with the Enterprise when debris on the bridge fell on him, mortally wounding him.