Kai King is currently a Doctor at Pillbox Medical Center.
However, several years ago King was a notorious criminal in London. During his time as a criminal, he made several enemies who were eager to murder him. As a result, King fled the country to Los Santos and started a new life, determined to keep his past a secret.
When he first arrived in Los Santos, King engaged in petty crimes with other shady figures in the city. He soon discovered that crime in this new city was just as dangerous as back home.
After giving up on the crime scene, King found his calling by volunteering for the local Emergency Medical Services. Shortly after he began his volunteer work, the Chief of Medicine Serge Cross offered him an opportunity to become one of the first doctors employed at Pillbox Medical. King accepted the position, and has never taken his duty as a physician for granted.
Paranoia & Fleeing the City
Recently, King was left paranoid and angry, due to a string of unfortunate events revolving around his safety at Pillbox Medical.
King was approached by the lawyer Lees Grey, who informed him a mysterious hitman working within the hospital, and wanted him dead. During this time, he received phone calls in Morse Code to decipher, and found a note addressed to him with the phrase Memento Mori.
In a protective response, King pushed many of his loved ones away (notably leading to Evita Nimm resigning as his secretary.) Soon after, Lees Grey also disappeared, causing King to tip over the edge. He opted to take an extended leave from Los Santos, for the safety of himself and others.
Back to Los Santos
After a much needed vacation--and a work suspension--King returned to his work at Pillbox Medical. Some time after his return, Kayden Steele sent him on a wild goose chase that ultimately hurt his friendship with Andrew Ducksworth.
In spite of these incidents, King hasn't lost his determination to save lives and protect the friends he's found in Los Santos.