Pete met MacGyver while tracking the international assassin Murdoc. Little is known about Murdoc. He is, and has been, the best in his line of work; his methods are, in his own words, "quick, neat, untraceable." His mastery of makeup and costuming have made him difficult to identify, and he never leaves loose ends - except, of course, in the case of MacGyver and his friends.
Thornton was impressed with MacGyver's ingenuity - after all, he'd used a paper clip, a wrench, and shoelaces to help them escape two men armed with bazookas. MacGyver then went to work at the DXS for Pete. Over the years, their friendship became so strong that he moved to the Phoenix Foundation when Pete was appointed Director of Operations.
MacGyver, or "Mac," as his friends call him, is a master of on-the-spot improvisation. He can use ordinary household objects to get himself and his companions out of trouble. All he carries with him is a Swiss Army penknife and, occasionally, a roll of duct tape. He carries no gun, having forsaken firearms after a traumatic childhood incident, and tries to avoid violence. He is fiercely loyal to his friends; his enemies will find him a clever, resourceful, and uncooperative opponent.
Whenever Jack Dalton enters MacGyver's life, things always seem to get more complicated. He's always got something up his sleeve, and it's usually a get-rich-quick plan that backfires. He grew up with MacGyver in Mission City, and moved to California, where he ran a short-lived taxi service before setting up a private airline, Fly-By-Night. Subsequent enterprises include Jack-Be-Quick Messenger Service and his current business, Dalton Air. Mac has learned to avoid Jack Dalton like the plague, for when Jack appears on the scene, trouble is sure to follow. He can tell when Jack's lying when his left eye twitches.
An aspiring singer and actress, Penny Parker is one of those people, according to MacGyver, who needs "looking after". She met MacGyver at a Bulgarian airport, but not under the best of circumstances; both were detained after police found Penny's jewels (which were later revealed to be the stolen crown jewels) in MacGyver's pocket. After a happy ending, Penny appeared again in Los Angeles, having "borrowed" Mac's apartment while she earned a living as a singing telegram. She enlisted MacGyver's help in solving the mystery of her aunt Betty's house and, presumably, is still trying to make it as an actress.
Mac's most unusual trait is his fear of romantic commitment. This fear, which has stifled many a relationship, stems from his previous experiences. His father and his grandmother were killed in a car accident when he was twelve years old; his mother died of complications from a stroke when MacGyver was on assignment overseas. He worries that whomever he becomes close to will die, just like his parents and his grandmother did.
Despite his misgivings about commitment, MacGyver remains the eternal optimist. He firmly believes that the world can and will change for the better - one person at a time.