Christopher Plummer showed why his reputation is anchoring this summer's slate of offerings at the Stratford Festival by turning in a terrific performance as Prospero in The Tempest. At the age of 80, he was a commanding lead in this generally strong take on one of Shakespeare's last works. The modern indoor space at the Destival Theater gave this production the opportunity to do a lot more with effects to emphasize the magical qualities in the story: a hydraulic stage, extensive use of the trapdoor, dropping Ariel in from the ceiling, and top-notch lighting and sound design all added to the supernatural ambience.