by Lester Del Rey (Author)
Bob Wilson, a student of language science, is hurtling through space on the greatest spaceship ever built. Just before landing on a satellite of Jupiter, it is mysteriously hit.
On Ganymede, Bob and his biochemist father find their resourcefulness challenged by a deadly plague which threatens the population of the small colony. A little girl's strange tales of friendship with beings from Jupiter lead Bob to the real test of his interrupted studies: communication with alien Jovians, who have no language as humans know it.
Can Bob solve this problem, and can the colonists find an antidote for the plague? A suspenseful and engrossing tale of space exploration and colonization...and first contact with a truly alien race of beings!