With degrees in astronomy, chemistry and education, it should come as no surprise that Harry Clement Stubbs - better known to SF readers as Hal Clement - produced some of the field's most compelling, scientifically literate work. This omnibus contains the clever alien-planet-with-a-twist novel ICEWORLD; the ground-breaking CYCLE OF FIRE, with its 40-year-long seasons; and CLOSE TO CRITICAL, from his celebrated Mesklin sequence.