Lawnmover crime

Today, I was more than slightly bothered to find that my lawnmover no longer managed to cut the grass. It started up fine, so there was no problem with the power, but it just didn't sound quite right.. somehow quieter.. and when moving it across the grass, it just sort of flattened it, as if it didn't have any blades at all! On closer inspection of the underside, I couldn't believe my eyes.. the blades WERE missing.. all that was left was just the ring which used to hold them. What?! I just don't get it.. I haven't removed the lawnmover blades, James hasn't removed the lawnmover blades, I seriously doubt any of our guests have felt the need to remove them.. so where have they gone in the space of time between the last time I cut the grass at the beginning of May and now? What makes it even stanger is that I checked with Stuart that it was supposed to have plastic blades, and that I wasn't just being stupid, and he told me that not only was it supposed to have plastic blades, there was also a spare set in the lawnmover box in the shed. Was being the operative word. Two pairs of missing lawnmover blades now. I can only think that someone, for some unknown reason, has got into our garden and nicked our blades! Why? I do not know.