It's time to fight for our right to wear matching socks
  1. Eaten by sock gnomes
  2. In a black hole
  3. In a dog's stomach
  4. In the vicinity of a moon bounce or trampoline
  5. Under sofa
  6. Narnia
  7. Glued to the washing machine
  8. On Dobby's feet
  9. Under my covers/foot of the bed
  10. In the lost sock pile
  11. Inside a pillow case
  12. Heaven
    Suggested by @ChrisK