He fills a stage with catamount grace, whirling through his numbers like a well-seasoned song-and-dance man. And that, of course, is just what 25-year-old Michael Jackson is. A performer since the age of 5, when he began fronting his family's now famous brother act, he has been strutting toward the top of the pop music world for two decades.

This year Jackson arrived. His high-octane Thriller album spawned a record six Top 10 singles and has so far sold more than 20 million LPs worldwide, second only to Saturday Night Fever. While his high-stepping videos to the singles Beat It, Billie Jean and Say Say Say were getting saturation play on MTV, Jackson took the form one step further with a $1.1 million, 14-minute film to accompany his Thriller title song. Starring Jackson and 1980 Playboy playmate Ola Ray as high school sweethearts in a mock monster movie, it played on MTV for several weeks and premiered in movie theaters last month, in time to qualify for a 1984 short-subject Oscar.

Yet for all his public exposure, Jackson remains an intensely private person, reclusive as Garbo. A Jehovah's Witness, he neither smokes nor drinks, is a strict vegetarian and fasts one day each week. "He's so pure it's scary," says Ray. "He's a space person." Echoes Quincy Jones, Jackson's producer: "Sometimes I think Michael is from another planet."

In 1984 he will cross much of this one when he joins his brothers on a major tour. Promoted by hyperverbose boxing entrepreneur Don King and sponsored—to the tune of at least $5 million—by Pepsi-Cola, the tour is slated to begin in May, hit as many as 50 American cities, move on to Europe and make more noise than any invasion since D day. In other words, a tour not unlike the performer himself. Out of this world.