Note: This was originally posted on my tumblr account as a (triple) drabble for the prompt "a bad memory." With Frodo, there were a lot to choose from, but here is one:
Even in the safety of the Shire, it takes only a snap of a twig, the clatter of a shutter, or the cry of a wild animal to awaken old and terrible memories…
Pain. That was all Frodo felt as he woke to the darkness of Cirith Ungol. His hands and feet were bound, but he was otherwise naked on the splintering floor. His body was limp, searing with lingering venom from Shelob's sting. His lungs ached with every breath. It took all his strength to pry his eyes open. When he did, he wished he hadn't.
Orcs emerged from the dark, contorted and deformed through the blur of his weak gaze. Hideous they were, dark and grotesque, with twisted smiles and jagged claws. They turned their yellow eyes to him and snarled. Whips snapped. A cord struck inches from Frodo's face, but he was helpless to move away. He felt a wave of nausea pass over him. A groan forced its way through his heaving lungs and up his parched throat.
The orcs laughed. The deep guttural sound echoed off neglected walls and shook cobwebs. It was a terrible sound: more fearsome than the screeches of bats and the howls of wargs.
Yet it is not the sickening laughter or the crack of the whip that haunts Frodo most. What wakes him at night, what tangles him in sweat-drenched sheets, is the dread that filled him when he managed to lift a finger to his neck and felt nothing but raw aching skin where the Ring had once hung.