Michael Cart (Booklist, February 15, 1998 (Vol. 94, No. 12))
What's a "gump," you ask? Why, it's a grassy bump that's actually a hidden door. Every nine years it opens--for nine days--to reveal a tunnel to another world, a magical island "so beautiful that it [takes] the breath away." Every country has a gump, it seems; Great Britain's is located under platform 13 in an abandoned railway station near the River Thames. Nine years before this story starts, the island's baby prince had been kidnapped when, on a lark, his nurses took him through the tunnel to London. Now it's time to bring him back. Entrusted with this responsibility is an unlikely group of rescuers: an ancient wizard, a fey, a yodeling ogre, and a very young hag named Odge. What chance do they have against the vast wealth and resources of the kidnapper, Mrs. Trottle, whose favorite perfume is called Maneater? Not much, frankly, especially since they're pledged not to use magic. But, then, if it were an even match, there wouldn't be much of a story. As it is, the plotting is occasionally a bit perfunctory--readers will spot a narrative-driving case of mistaken identity almost immediately--but fantasy lovers will probably excuse that for the sake of the author's ironic wit and her skill at introducing an amazing variety of supernatural, folkloric, and imagined entities who never fail to excite the readers' imagination and sympathy (and adults will enjoy meeting a certain former prime minister thinly disguised as an especially brisk Harpy with a handbag!). Category: Middle Readers. 1998, Dutton, $15.99. Gr. 4-7.

Kirkus (Kirkus Reviews, 1998)
Old magic breaks loose in modern London to rescue a kidnapped prince in this droll, if formulaic, farce from Ibbotson. When wealthy Larina Trottle decides she wants a child, she snatches the first baby that comes along, leaving distraught royal parents on the other side of an ancient gate (Platform 13, in an old Tube station) that opens once every nine years. Nine years later, through the gate comes a rescue party: an invisible giant, a very old wizard, a fairy, and a young hag-in-training, Odge Gribble. But Raymond Trottle is a fat, selfish, greedy, stupid, thoroughly spoiled child. Reluctantly, with the help of the Trottles' thoroughly likable kitchen boy Ben, the rescuers set about their task, without reckoning just how difficult crafty Larina is going to make it. Ibbotson strews her tale with magic creatures and stock villains, including bodyguard/assassin "Soft Parts" Doreen, armed with deadly knitting needles, a terrible lake monster who gives a delicious new meaning to the term "clear skin," and a band of harpies, horrible to behold in pearls, tight perms, and stretch tops. At the very last moment comes the revelation that Ben, not Raymond, is the true prince, and Odge engineers the happy reunion. With scrawled, comic black-and-white drawings by Porter, it's not exactly Roald Dahl, but Ibbotson is at least a distant cousin. 1998, Dutton, $15.99. © 1998 Kirkus Reviews/VNU eMedia, Inc. All rights reserved.

Horn Book (The Horn Book Guide, Fall 1998)
A complicated fantasy predicates an Atlantis-like island ruled by a beloved monarchy and populated by various magical creatures. When the island's baby prince is kidnapped, a troupe of the magical creatures attempts to rescue him. The star of the show is the young hag, Odge Gribble, whose ingenuity wins out in the end. Amusing at times but very British and a trifle long. Category: Fiction. 1998, Dutton, 231pp. Ages 9 to 12. Rating: 4: Recommended, with minor flaws.