The mystery of the missing sock has been solved! I had just about given up when I finally spotted it in the “wine cellar” (read: in the utility room near the door to the garage). It was camouflaged against the fauxriental rug (a wink at the quality of our wine “collection”).
Mr. Kitty has been running off with soft knitted items since before I took up knitting. He used to steal my sweaters out of the laundry basket and I finally had to give him a decoy, dedicating an old cheap sweater to the task. (It’s acrylic but there’s a touch of mohair, enough to convince him it’s worthy of dragging around.) It got kinda grody and I had tucked it away when we had visitors, but clearly it’s time to get the decoy back out!