American actor James MacArthur was the adopted son of stage legend Helen Hayes and playwright Charles MacArthur. Despite his mother's insistence that James have a normal childhood, it was difficult not to be intoxicated by the theatre when growing up around the greatest acting and literary talent in the '40s. At age 8, young MacArthur appeared in a stock-company production of The Corn is Green. Fresh out of Harvard, MacArthur became a movie juvenile, specializing in tortured-teen roles in such films as The Young Stranger (1957) and Disney's Light in the Forest (1958). Outgrowing his somewhat charming awkwardness, MacArthur was less satisfying as a standard leading man, and by 1967 he was wasting away in pictures like The Love Ins. That same year, the pilot film for a new Jack Lord cop series, Hawaii Five-O, was screened for a test audience. The group liked the film but not the young man (Tim O'Kelly) who played Lord's assistant, deeming him too young for the part. Hawaii producer Leonard Freeman then called upon 30-year-old MacArthur, with whom Freeman had worked on the Clint Eastwood vehicle Hang 'Em High. From 1968 through 1979, MacArthur played Hawaii Five-0's detective Danny Williams, always handy whenever Jack Lord felt the need to snap "Book 'em, Danno." Though the series enriched MacArthur and made him a vital member of the Honolulu society and business world, the actor finally packed it in after 11 seasons, when it seemed as though he'd be Danno forever (the show continued for one more season). Too wealthy to care about a career at this point, James MacArthur still took an occasional role into the '80s; his most prominent post-Hawaii assignment was the 1980 TV movie Alcatraz: The Whole Shocking Story, in which he played a rare non-sympathetic character. MacArthur died in October 2010 of natural causes at age 72.