From PEOPLE Magazine Click to enlarge
Some people dread work, but try keeping Patrick Swayze away from a day at the office. On July 20, the 55-year-old actor, who has been undergoing treatment for pancreatic cancer since last winter, looked fit and was in great spirits as he boarded a flight from L.A. to Chicago to start shooting his new A&E drama series, The Beast.

"He was walking pretty slow and being careful," says an onlooker. "But his arms looked pumped like he had been working out." Swayze, who has been spending time with wife Lisa at their ranches in California and New Mexico, also seems to marvel at his rebound. "I'm a miracle, dude," he told a bystander. "I don't know why." Friends credit his determination. "You can tell there's something special about him," says Beast costar Sarah Danielle Madison. "He's so focused."

While shooting his role as a tough FBI agent in The Beast, Swayze will continue his cancer treatments, but his castmates don't expect him to take it easy. "In his mind, nothing was wrong," says actor Larry Gilliard Jr. of Swayze's attitude toward his illness. "That's the kind of person he is—very positive."