Chimera

Corrected entry: After Frodo is paralyzed by the spider and taken captive, his captors take some of his personal effects - clothing, chain mail, and, of course, THE RING. Whoever took that ring should have been compelled to put it on (at which point Sauron would have seen it and sent his minions to recover it), and would not have just left it lying around somewhere for Sam to find later.