The great Dr Seuss once wrote a little book called Yertle the Turtle about the construction of a turtle pyramid so high that the top turtle could see everything for miles around. No sooner was the final turtle added to this vertiginous structure than Yertle, a little chap at the bottom, burped, bringing the edifice crashing down. The top turtle found it humiliating, but the others lived happily ever after.

Our story today is very similar, except that the little chap who burped was called Ninja. The top turtle, while humiliated, still ended up pretty rich, but it will be a long time before we know whether everyone else lives happily ever after.