It sounded like a terrific comic-strip plot. A pretty young heiress is kidnapped. She joins her captors and symbolically changes her name. Credit cards and taped messages are sent to her parents. Milton Caniff, the creator of Steve Canyon, had been working on such a series of strips for about five weeks when the news of the kidnapping of Patricia Hearst first broke last February. Caniff, who works about 15 weeks ahead of publication time, decided he had to junk the story.

"It would have looked like I was making fun of the Hearst family," says Caniff, who knows the Hearsts personally. Working overtime in his Palm Springs, Calif. studio, Caniff has whipped up a new plot, involving Canyon's family problems, which is currently appearing in the 650 newspapers in which he is syndicated. Caniff, who frequently develops his plots from news headlines, got his kidnap idea from last year's abduction of J. Paul Getty III. "I decided to make the victim a girl," Caniff explains, "because people are 95% more interested in women in dire circumstances than they are in men." The idea of having the young victim join her captors was just an impulsive twist in the story.

Twice before in Caniff's career of more than 40 years, his comic strips have anticipated news events. In 1944, when he was drawing the now defunct "Terry and the Pirates," he orchestrated a make-believe British glider invasion of Burma. "It was exactly what the British were doing," Caniff recalls. The British were convinced there had been a security leak. A year later the cartoonist read that American soldiers had been picked up in Hong Kong wearing black shoes instead of the regulation brown ones. Caniff surmised that they were actually Navy men who were setting up a network of radio stations in China. He put the idea into his strip, using "Happy Valley" as the code for the network.

"Not only was I right about the radio stations," says Caniff proudly, "but I even had the code name right." The Navy, it turned out, had taken "Happy Valley" from a race track in Hong Kong. Caniff's had come from a boys' camp in upstate New York, but the coincidence was enough to send the FBI knocking at the cartoonist's door.

In spite of his record, Caniff doesn't think his ability to outguess events is particularly unusual. "My plots mostly start with a news item," he says. "I just take the available data and run it through my skull. Of course, I am always thinking about possible monkey business."