Tremors II: Aftershocks elucidates the transformation of Graboids into subterranean worms that hunt via sound waves, as Earl Bassett (Fred Ward), a hero past his prime, rejoins forces with new associate Grady Hoover (Christopher Gartin) to hunt them down at a Mexican oil field, discovering they have evolved into swift, Shrieker-like creatures that hunt via heat signatures, prompting them to collaborate with Burt Gummer (Michael Gross) and geologist Kate Reilly (Helen Shaver) to combat the multip