B.C.
There's a space/time vortex in the dryer.
The socks use this portal to travel back and forth to the Land of Lost Socks.
Actually there is a vast sock army which is trying to take over the world.
Ever see one lonely sock by the side of the road?
Yep - sock intelligence collecting information.
The dark socks are ninjas with special forces skills.
I've actually resorted to washing socks separately from the rest of the laundry.
It helps to a degree, but the odd sock still wanders off every now and then.