K-9, unlike most cyberdogs, is fully sentient and has been modified with vocal organs, allowing him to communicate verbally in several languages. His high intelligence allowed him to develop his own sense of morality, which brought him at odds with Dr. Schreber and his unethical experiments, despite being programmed to work as his assistant, and he came to hate the sadistic scientist with a passion. This eventually culminated in him one day biting Schreber, who then punished him by disabling his legs, forcing him to stand still like a statue and watch the doctor's horrible experiments.
After getting his motivator repaired, K-9 was left in NCR by the Chosen One so that he could receive necessary repairs from Dorothy and, not long after his recovery, Dr. Henry (who had been placed in critical condition after being reportedly assaulted by the Chosen One some time earlier). Dr. Henry, afraid that too much information about the Enclave would be obtained from K-9, attempted to destroy the cyborg, but was stopped by cyberdog and Dorothy, who suspected what Dr. Henry was planning. The NCR government used the attack as an excuse to confiscate K-9 and cyberdog in order to learn more information about the Enclave as well as what makes the two of them "tick." At last report (and over Dorothy's objections), K-9 and cyberdog were disassembled and analyzed. Structural damage during the disassembling is reported to have killed them both.
Fix K-9: He can be found in Dr. Schreber's office at the Navarro facility. He is non-operational when first found, and requires some physical repairs.
To obtain K-9, you must complete two requirements:
The player must repair K-9's leg mechanisms with a drive mechanism. One is available in the mechanic's shop right on the Enclave base inside a locker. Using this part on K-9 will fix him (this does not use the Repair skill); no other repairs are required.
The player must kill Dr. Schreber. It is recommended that he/she closes the sound lab door first, considering it is sound-proofed, and will prevent a fight against the rest of the base.
K-9 will not join a player with low Karma and negative reputations. However, if K-9 is in the party and the player becomes a Childkiller or their karma drops below -101, he will leave permanently.