Home › Norby › Norby and the Invaders N Norby and the Invaders by Janet Asimov · 1985 · Book 4 of Norby Buy on Amazon About “Norby and the Invaders” Norby and the Invaders is a 1985 book by Janet Asimov. It is book 4 of the series Norby. Book details First published 1985 ← Norby and the Lost Princess All Norby books in order Norby and the Queen's Necklace →