"... first published in Great Britain under the title The mystery that never was by William Collins Sons & Co. Ltd in 1961. First published by Award Publications Limited 2004 as The young adventurers and the mystery that never was"--T.p. verso.
The riddle that never was by Enid Blyton. ISBN 9781841357386. Published by Award Publications in 2009. Publication and catalogue information, links to buy online and reader comments.