Although BOSCO does not have a neck, or a nose, and has long flapping ears, an antenna surrounded by six little curls on top of his head, and eight eyes situated around his noggin, his appearance is extremely pleasant to the people on planet Earth, and his smile, his extraordinary talents, and his human-like sensitivities endear him to everyone he meets.

Bosco was sent to Earth, by the Board of Directors that govern the Moon, to confer with the President of the United States and other powerful dignitaries throughout the planet concerning the Moon's security. The Lunarians were worried that Earth's exploration in space would eventually cause trouble for them. Nevertheless, while Bosco is returning to the Moon after successfully completing his mission, he unwittingly loses control of his ship, the SPHYR-BALL, and must make an unscheduled landing in Cahoon Hollow, a small town in Massachusetts. CORA DeHAAS, a clever and spirited twelve-year-old girl, accidentally sees BOSCO, and after a series of humorous incidents she and BOSCO meet and become friends. Cora's father, Dr. DeHaas, is a brilliant scientist who has concocted a miracle drug that would forever rid the world of the COMMON COLD; however, when it's discovered that it has a unique side affect so devastating that in the wrong hands could enslave humanity, the doctor becomes a target for a criminal organization led by the notorious madman, Rolando Pomfrey. Dr. DeHaas, en route to Europe to confer with colleagues concerning the drug, is abducted by Rolando Pomfrey and his thugs; they feel that with the doctor's formula solely in their possession they could conquer the world.