Alfie Green and the Supersonic Subway — Joe O'Brien

When the Emerald Cactus in the Desert of Doom explodes, Budsville is covered in sparkling green sand ... Soon the evil Desert Elves will arrive on their Scorpion Chariots. How can Alfie stop them? A very special lawnmower hidden in a secret subway under Grandad's shed might do the trick - and it might help Alfie and Fitzer in the go-kart race, too!