We're entering the era of the geriatric superhero, as such Baby Boomer icons as Indiana Jones and John Rambo limber up for the fourth chapters in their ongoing escapades. Let's hope they have aged as resiliently as John McClane.

"Live Free or Die Hard" doesn't strain for novelty, staying comfortably within the plot conventions of the earlier episodes (and of Bruce Willis' recent run-the-gauntlet thriller "16 Blocks"). Mr. McClane, who has "borrowed" an unmarked car to visit his resentful daughter at her New Jersey college, is assigned to pick up a nearby free-lance hacker linked to a high-security breach in the nation's...