Frodo the Hobbit (played by Elijah Wood still looking like a deer in the headlights) has the ring. He and Samweiss the Hobbit (chubby little Sean Astin) are moving toward the Mountain of Fire with the help of Gollum (played by The Weekly World News's Batboy)
Mortensen and Tyler's relationship is so thinly sketched in the first movie, that when they speak here it has the emotional impact of a dumpster dive.
Plus, it's sort of laughable when characters on screen can be easily identified as good or evil purely based on the greasiness of their hair, and yet the people in the movie can't tell. "What! You mean that guy dressed all in black with the ashen skin and greasy hair was a bad guy? Damn!"