The central theme [of The Homeward Bounders] is appallingly probable. What better explanation of the mess we are all in than to have it the result of the dispassionate manipulation of Them. [Edward Lear and Thomas Hardy] had their own words for it, and now Diana Wynne Jones enters the big league with a story of cosmic proportions. It is some measure of her success that she is believable, humane and humorous. What is more, she contrives a kind of happy ending, but denies happiness to her own hero. When They have been defeated, Jamie is left alone on his travels, as the anchor who holds all the worlds in place. It could be worse. He has friends in many worlds, but wandering is a lonely business.
As you may gather, there are difficulties in this book. Reading it is not to be undertaken lightly. It demands concentration and total suspension of disbelief. The rewards are a magnificent story, lots of good humour, shrewd characterisation, and a deeply disturbing theme presented with deep wisdom and rich understanding. Miss Wynne Jones' biggest book to date and probably her best, too. Fortunate those children, and adults, who can meet its challenge. (p. 213)
Marcus Crouch, in his review of "The Homeward Bounders," in The Junior Bookshelf, Vol. 45, No. 5, October, 1981, pp. 212-13.