Sully is a sphere dealer at a flea market. It doesn't pay much - Alex Holliday's stores have muscled out most of the independent sellers - but it helps him and his mum make the rent. No one knows where the brilliant-coloured spheres came from. One day they were just there, hidden all over the earth like huge gemstones. Burn a pair and they make you a little better: an inch taller, skilled at maths, better-looking. The rarer the sphere, the greater the improvement - and the more expensive the ...

Tenth title in the worldwide bestselling Treehouse series from Andy Griffiths and Terry Denton, now in Hardback.