What you might have missed in the trippy paranoid thriller A Scanner Darkly--other than the entire movie, which wasn't exactly a box-office smash--is the frightening vulnerability that Robert Downey Jr. brings to what is basically a throwaway comic part: Barris, one of the geek chorus of drug-addicted burnout buddies who hang around with the movie's hero, Bob Arctor (Keanu Reeves). They're all losers--end-stage versions of the lovable slackers director Richard Linklater is so fond of--but Barris is the king of losers, the household crackpot authority on everything: manic, hyperkinetic, always talking and building gadgets that don't work and lecturing everybody on the sorry state of reality.
This could have played like standard wacky sidekickery, except Downey, 41, shows the fear behind the funny. Barris doesn't know any more than anyone else, he just talks faster and louder. If he slows down for an instant, he's lost.
There's another level to the performance too: Downey came famously close to ending up a drug casualty in real life. "You'd think I'd stop at some point and go, 'This reminds me of when ...'" says Downey. "But to me it was a kind of prophetic science-fiction tale. The substance abuse was a metaphor."
"It's one of those gonzo unique occurrences where the right part meets the right actor," says Linklater. "And he brings every bit of his own energy, intelligence and humor to it."