Few actors are authoritative and vital for seven decades. But Christopher Plummer was as formidable as ever in his last years.

“Knives Out,” Rian Johnson’s 2019 homage to Agatha Christie, boasts one of the most electric ensembles in recent years. The most commanding presence in the movie, however, might be that of Christopher Plummer, the mightily versatile actor who died Friday at 91.

It is probably fair to say that few film actors remain vital and authoritative even after working steadily for nearly seven decades. But that was not the case with Plummer, a prolific and sometimes mischievous performer who enjoyed a remarkable renaissance in his final decade.