He can only have wanted it as a way of creating a mystery. Then I saw that this applied to all the other outrageous details. They were devilish enough; but it wasn’t mere devilry; there was a rag of excuse; because they had to make the mystery as contradictory and complicated as possible, to make sure that we should be a long time solving it — or rather seeing through it. …
They had to give us an Insoluble Problem.