An actor's life is such a chancy thing. Success can have as much to do with serendipity as with talent. An agent has a client who has a boyfriend who is taking acting lessons. But the agent is busy with other clients and likes to pick his own talent.

In the Manhattan of the 1950s -- much like today -- acting students were everywhere. And Hilly Elkins, an agent, was working to get actress Neile Adams work on Broadway. One day a gadabout by the name of Steve McQueen, a former Marine who would be admitted to the esteemed Actors Studio, who had been abandoned by his mother in Indiana as a child, showed up outside Carnegie Hall and said to Adams, "You're beautiful."

"You're beautiful, too," she replied.

Adams soon persuaded Elkins to take on McQueen as a client, although the agent initially thought McQueen might be trying to hustle Adams out of some dough.

McQueen and Adams eventually married. And soon enough, McQueen got his first starring role in a new TV series, "Wanted: Dead or Alive," which premiered in 1958. Then it was on to movies and fame -- he wasn't long for the role of starving actor -- with roles in "The Magnificent Seven," "The Great Escape," "The Thomas Crown Affair," "Bullitt," "The Cincinnati Kid" and "The Getaway." His most potent movies were all 1960s-era films, with McQueen playing an enigmatic rebel. He seemed to fit the times. His 1970s roles were not as important, with "Junior Bonner," "The Getaway" and "Papillon" being the standouts.

But fame begat a reclusiveness and arrogance in McQueen. In his mid-forties, he became hard to reach, even charging movie executives fees just to read the scripts sent to him. "What Steve had," recalls Elkins, who continues to work in Hollywood, "was total self-confidence -- and total self-doubt." Elkins believes McQueen felt he'd somehow be found out as the kid who had once been consigned to a California reform school. "It's what gave him his edge," says Elkins.

This year marks the 75th anniversary of McQueen's birth, March 24, 1930. November will mark the 25th anniversary of his death Nov. 7, 1980, of lung cancer.

The anniversaries are being marked by a McQueen revival. The first season of "Wanted: Dead or Alive" has just been issued by New Line Cinema as a four-disc DVD set, totaling 36 episodes. This month, Warner Home Video released a boxed set of six movies -- "Bullitt," "The Cincinnati Kid," "The Getaway," "Tom Horn," "Never So Few" and "Papillon" -- that is accompanied by a documentary, "Steve McQueen: The Essence of Cool." MGM also issued a four-movie boxed set collection in May.

The movies and documentary show what an accomplished figure and screen presence McQueen could be. But he was also petulant, difficult, tortured and quite paranoid.

In "Wanted," McQueen played a bounty hunter. This was during the golden age of the TV western: The year "Wanted" premiered, "Gunsmoke," "Wagon Train," "The Rifleman" and "Have Gun, Will Travel" were all highly rated TV fare. It took some convincing on Elkins's part for McQueen to get the "Wanted" role.

"The producer thought Steve was too short," says Elkins. McQueen was under 5-9, and he came to the party with a chip on his shoulder. In "Wanted," he didn't wear a pair of fancy six-shooters. Instead, he wore a sawed-off Winchester on his right hip; it looked cumbersome but he handled it with finesse. "The gun was Steve's idea," says Elkins.

Western fans will appreciate "Wanted" for its austere black-and-white look and for the growth of its star. McQueen plays off other actors with his ocean-blue eyes. You'd come to see it in larger ways in later years, but it's also in evidence here. He's always thinking, maneuvering with them. He's the one on-screen playing chess while standing up. There was something else about the early McQueen that he carried throughout life: He pruned scripts, taking words away from his own character, choosing to act in silences, with body and eyes.

There's a scene in "Papillon," the movie about Henri "Papillon" Charriere's prison escapades in French Guiana, where McQueen, in the title role, is on a ship being taken to prison. He has agreed to watch over Louis Dega, a prisoner played by Dustin Hoffman. The camera pans to two cons getting ready to do something nasty with a knife to Dega. Then the camera pans to McQueen, lying in a hammock. His leap from the hammock to the floor is done so stealthily you'd think a tiger had just jumped down instead of a man.

It was on the big Technicolor screen where McQueen exploded.

"The Magnificent Seven," which opened in 1960, has become a classic. It's a remake of Akira Kurosawa's "The Seven Samurai." There was tension on that set, principally between McQueen and several of the other young actors (Robert Vaughn, Charles Bronson, James Coburn) and the movie's lead, Yul Brynner. McQueen hated being upstaged. In the opening scene, riding up to Boot Hill to deliver a corpse, Brynner lights a cigar. McQueen pulls out a cartridge of buckshot and shakes it to his ear. You can see it got Brynner's attention. The movie was a hit. "A triple," says Elkins. " 'The Great Escape' was the home run."

The latter was directed by John Sturges (who also directed "Seven"). It was also on "The Great Escape" that the "difficult" McQueen began to emerge. He walked off the set, believing that co-star James Garner was getting too much attention from the director. Studio bigwigs talked McQueen into returning and added a motorcycle scene in which McQueen attempts to escape the Germans, testing their level of security at the camp. McQueen rides the thing like it's an appaloosa.

Though he was one of the most popular actors of his generation, McQueen never won an Oscar. His only nomination came in 1967, for "The Sand Pebbles," in which he played Jake Holman, a valiant sailor aboard an ill-fated American gunboat in China.

McQueen never knew his father, and being abandoned by his mother for a while seems to have scarred him terribly, giving him a brusque and distant personality. In the documentary, some of McQueen's friends seem full of anguish as they try to explain the petty jealousies and womanizing, the paranoia. They seem taken aback still by his having so much good fortune and walking in a darkness much of his own making.

McQueen was taken with the West and with haunted figures. In perhaps his most nuanced performance, he played a real-life bounty hunter in "Tom Horn," his next-to-last movie. Horn was a range detective who roamed Wyoming killing cattle rustlers on orders from cattle barons. It was believed he mistakenly killed the 14-year-old son of a sheepherder, and for that Horn was tried and hanged. In the movie there are melancholy scenes of McQueen sitting beneath the dark western sky, riding across a barren and snow-covered landscape all alone, staring into the distance. By the time of "Horn," McQueen's face had taken on age and lines. The cancer that would kill him had begun to creep in. Pain brought soul to his face, and McQueen played the doomed Horn beautifully. On the gallows, Horn looks at the sheriff and says, "Keep your nerves, Sam, 'cause I'm gonna keep mine."

There were few movies in the last years of McQueen's life. His marriage to Ali MacGraw fell apart. He was using drugs. He married again. He became a recluse.

It was a mighty hill that Terrence Steve McQueen had to ascend. But give him credit: The abandoned child made some kind of life in this world, gambling and often winning. "When a kid didn't have any love when he's small," McQueen once said, "he begins to wonder if he's good enough." He was.

Steve McQueen's "Wanted: Dead or Alive" TV series has been released on DVD.Steve McQueen as a rebellious, and resourceful, prisoner in 1973's "Papillon" and as the haunted title character in one of his last films, "Tom Horn," left. The actor, who would have turned 75 this year, died of cancer in 1980, the year "Tom Horn" was released.The first season of "Wanted: Dead or Alive," on which McQueen played a bounty hunter, has been released on DVD to mark the anniversaries of McQueen's birth and death.