With directorial tongue firmly in cheek, Leonard Nimoy again takes the helm (he had begun his career with the lumbering third episode), in this environmentally-minded installment which sends our heroes back in time to 1986 San Francisco. Spock gives a Vulcan pinch to a punk, Kirk gets lost

on a bus, and we learn the importance of saving the whales. (A huge space probe is threatening to destroy 23rd-century Earth unless a whale--by then extinct--can be found for it to "chat" with.) By far the silliest and most self-mocking of the series, with the interplay between Spock and Kirk

veering somewhere between Hope and Crosby and Cheech and Chong, but also one of the most successful, grossing around $110 million.