But then it happened again. And – here I will spare some details – this time there could be no doubt. The upstairs neighbours and I racked our brains. Who had we so annoyed that this was their revenge? Should they have offered more for that secondhand printer? Was my stint on the Polaroids stall at the school fete really that bad? Our only clue to the culprit, unless we were to go down the DNA route, was that they would need to be pretty limber.