Karazin was an icy planet in the Karazar system, located in the Tabula Rasa. It was inhabited by the Taubat.
The Taubat considered the generation of power to be a religious action, and their temples were built up around power generators. However, when Karazin emerged into normal space from the anomaly generated by Project Shiva, the local temple was badly run down and desperately in need of repairs. Due to radiation leakage from the temple's generator, the population of Karazin began to suffer from radiation sickness. Unsure of the cause of this plague, the Taubat on Karazin begged for assistance from their government, who sent out a distress call, which was received by the Federation.
As Starfleet probes had determined that the Taubat species was spread throughout the Tabula Rasa and thus appeared to be capable of some form of warp travel, the Federation decided to respond. On stardate 8987.8, they established a medical colony on Karazin with the hope of making a successful first contact. Federation doctors quickly determined the "plague" was in fact radiation sickness being caused by the local temple, and Federation engineers were able to gain access to the temple, effect repairs, and prevent the facility from suffering a critical overload. The successful curing of the plague resulted in (apparent) good relations between the Federation and the Taubat, which would last until they awoke the Metar from stasis.
The Klingon Empire also established a colony on Karazin at the same time, as part of their ongoing attempt to annex the mineral-rich worlds that had appeared from the anomaly. They launched an unprovoked attack on the Federation colony and tried to conquer the local Taubat settlements, but their initial strike was fought off by Starfleet. (TOS video game: New Worlds)