Continuing the plot of the previous film, it intercuts three storylines. Frodo and Sam continue their journey towards Mordor to destroy the One Ring, meeting and joined by Gollum, the ring's former keeper. AragornLegolas, and Gimli come to the war-torn nation of Rohan and are reunited with the resurrected Gandalf, before fighting against the legions of the treacherous wizard Saruman at the Battle of Helm's DeepMerry and Pippin escape capture, meet Treebeard the Ent, and help to plan an attack on Isengard, fortress of Saruman.