If you think jury duty’s a drag, consider how much worse sitting in judgment could be if, on the first day of the trial, you discovered that the defendant’s been accused of a terrible crime for which you were in fact responsible. That’s the hook of Clint Eastwood’s latest — and some fear last — feature, “Juror No. 2,” a slightly preposterous but thoroughly engaging extension of the 94-year-old filmmaker’s career-long fascination with guilt, justice and the limitations of the law.

In movies where Eastwood acts, guns go a long way to resolve problems the system can’t. But the director does not appear in “Juror No. 2,” a moral-minded courtroom drama in which Nicholas Hoult plays the lone holdout in a murder trial. The film may open on a note of idealism, but it quickly turns cynical as Hoult’s character, “perfect” husband and upstanding citizen Justin Kemp,...