When Alfie and Angel Young arrive at ParkwayGrange for the Easter holidays they are introducedto Mylor - a magnificent, unbelievable giant of ahorse with a very special secret. For Mylor is anelectronic miracle. A horse built by an eccentricProfessor for the purpose of winning the EnglishGrand National. Powered by the sun's rays andperfect down to the last detail, Mylor has ten timesthe strength of any living horse and a speciallydesigned interior which allows him to be controlledby the children. An adventure crammed full of excitement soonfollows, and as the story races towards itssupercharged climax it is obvious that someonewill stop at nothing in their efforts to destroy Mylor.Suddenly a new undreamed-of nightmare faces thechildren, and then everything depends on the instinctand love of The Most Powerful Horse in the World