Book I, Chapter 12: "Flight to the Ford" Aragorn discovers that a shard of the Black Rider's sword remains lodged in Frodo's shoulder. He tends to Frodo's wound with the healing leaves of the athelas plant, but his condition remains perilous. The company leaves Weathertop as quickly as it can, heading for the Ford of the Bruinen River, beyond which lies Rivendell. Aragorn discovers an Elven jewel on the Last Bridge before the Ford, but does not know why it was there.

As the company nears the Bruinen, they meet Glorfindel, an Elf sent from Rivendell. He tells them that Gandalf still has not reached Rivendell. He also tells them that he has encountered several Black Riders, five of whom are in pursuit. Glorfindel places Frodo upon his own horse. At the Ford, when the Riders are upon them, Glorfindel urges Frodo to ride ahead quickly. Frodo feels a strange reluctance to do so, and Glorfindel must urge the horse forward himself. Black Riders, however, wait ahead of Frodo as well. Frodo rides his horse across the Ford, but is followed into the River by some of the Riders. Frodo tries to defy them, but the Riders are undeterred. At the last moment, the waters of the River overwhelm the Riders; Frodo believes he sees "white horses with frothing manes" in the waters. He sees the rest of his companions, on the other shore, using fire to fight off the other Riders. Finally, Frodo falls and loses consciousness.