The Departure of Boromir - Aragorn searches for Frodo, but while he does, he hears Orcs nearby, and then Boromir's horn blowing. He runs quickly to Boromir's aid, but when he finds him, Boromir is already full of arrows and his horn is in pieces. Before he dies, Boromir admits he tried to take the Ring from Frodo, and tells Aragorn the Orcs captured "the Halflings." Feeling as though everything is in shambles, Aragorn kneels by Boromir and weeps. Legolas and Gimli find him in this posture when they arrive, having also heard Boromir's horn.
Legolas, Gimli, and Aragorn lay Boromir in one of the boats, arrayed with his weapons and broken horn, and send the boat over the Falls of Rauros. Examining the fallen Orcs in the area, they realize the Orcs bear the mark of Saruman, not of Mordor. They also determine Merry and Pippin were captured, but not Frodo and Sam, who appear to have taken their packs and a boat and left alone. Aragorn correctly reasons out the answer to this riddle.
Aragorn, Gimli, and Legolas decide to pursue the Orcs in hopes of recapturing Merry and Pippin, and they set off at a run.