No one lives in this land. Men once dwelt here, ages ago; but none remain now. They became an evil people, as legends tell, for they fell under the shadow of Angmar. But all were destroyed in the war that brought the North Kingdom to its end. But that is now so long ago that the hills have forgotten them, though a shadow still lies on the land.After fleeing Weathertop, Aragorn led the hobbits south across the Great East-West Road and into the Lone-lands. They traveled east, towards the distant Misty Mountains, for five days. The pain of Frodo's wound increased, but they did not sense the presence of the Black Riders. At the end of the fifth day, the ground began to rise as they turned to the north-east, and on the sixth day, they reached the top of the rise. They could see the Road sweeping around the feet of the hills, and to their right, "another river in a stony valley half-veiled in mist". 
~ Aragorn, Book I Chapter 12: Flight to the Ford
Early in the morning of the seventh day after their flight from Weathertop, that of October 12th, Aragorn and Sam descended to the Road and cautiously followed it eastward. After a mile or two, they saw ahead of them, at the bottom of a short, steep slope, the Last Bridge. 
To their relief, the bridge was not held against them, but Aragorn found in the mud of the bridge a beryl -- an elf-stone.  Taking the beryl as a sign of hope, they crossed the Last Bridge and passed into the Trollshaws. A mile or so beyond the bridge, they left the Road and entered a narrow ravine "that led away northwards into the steep lands on the left of the Road". The land here was a "sombre country of dark trees winding among the feet of sullen hills".
This new country seemed threatening and unfriendly to the hobbits. As they journeyed north, the terrain steadily rose into a jumble of ridges and valleys. On the heights, they could see "ancient walls of stone, and the ruins of towers: they had an ominous look".  Two days into the Trollshaws, the weather turned wet; their journey was cold and cheerless. On the night of October 16th, they camped on a "stony shelf with a rock-wall behind them, in which there was a shallow cave", and Frodo dreamed uneasily of a fading Shire.
The following morning the rain stopped. Aragorn scaled the cliff behind the stone shelf to get a view of their surroundings. He determined they had come too far north, and would need to find some way to turn southwards again.  After spending the day scrambling over rocky ground, they found a valley running southeast, the direction in which they wished to travel, only to find it blocked at the end by a high ridge. It was the end of the day, and, faced with choice of turning back or scaling the ridge, they chose to make the difficult climb.  At the top, they found themselves on a saddle between two high points. The land fell away steeply to the southwest. Upon this saddle they made their camp.
The morning dawned bright and fair. Aragorn and Merry surveyed the land from the height to the east of the pass. They discerned that they were now headed in the correct path, and determined that they must again make for the Road. After eating, they climbed down the southern side of the ridge; this was easier than climbing the opposite side had been. At the bottom, Pippin spotted a faint, overgrown path, seemingly made by strong arms and heavy feet. They followed it down a slope and left around the shoulder of a hill. Here the path ran under a cliff face overhung with trees. The cliff-face was set with "a door hanging crookedly ajar on one great hinge". Aragorn, Sam, and Merry managed to push open the door, revealing a shallow cave littered with old bones, empty jars, and broken pots: a troll-hole. 
Continuing on the path past the troll-hole, they plunged down a thickly wooded slope. Merry and Pippin, traveling ahead of the others, were terrified when they saw through the trees ahead a clearing, seemingly inhabited by trolls! Aragorn, however, was unconcerned, and indeed the inhabitants of the glade turned out to be the petrified remains of three trolls who had been exposed to the rays of the sun long ago. 
They continued to follow the path, and finally came out onto a high bank overlooking the Road. It was early evening, and the Road was quiet. They climbed down to the Road and followed it eastward as quickly as they could, but it was not long before they heard the sound of hoofs behind them. They scrambled up off the road into a patch of thick-growing hazels from which they could observe the road to see who approached.
At last the rider came into view and they saw that they needn't have been worried: the rider was the elf Glorfindel, of the house of Elrond, who had been sent to seek for Frodo. Glorfindel led them on into the night, and at dawn, they halted to rest.They slept until mid-morning, when Glorfindel awakened them and they again took to the Road. They moved with great haste, covering nearly twenty miles before nightfall, and finally camping where the Road turned right and, running downhill, made straight for the Ford of the Bruinen. The hobbits could perceive no sign of pursuit, but Glorfindel was anxious.
When they awoke, Glorfindel urged them on, for pursuit was swift behind them. That afternoon, they plunged into a "deep cutting with steep moist walls of red stone". The Road ran out from this natural tunnel into the open; beyond that was a long flat mile leading to the shores of the Bruinen.  Across the Bruinen lay the safety of Rivendell.
As the company surveyed the land leading to the river, five Black Riders emerged from the deep cutting they had just left. Frodo, mounted on Glorfindel's white steed, Asfaloth, sped forward toward the Ford. The five Black Riders leaped down the hills in pursuit. As the Riders passed, the rest of the company, instructed by Glorfindel, hastily kindled a fire in a small hollow beside the Road.
The four other Riders emerged from the trees north of the Road; two rode toward Frodo, and the other two to the Ford to cut off his escape, but Asfaloth proved swifter and Frodo reached the Ford, crossing to the eastern shore of the Bruinen, where the bank rose steeply toward the mountains. Weary and afraid, Frodo turned to look west, back across the river.
The Nine Riders gathered on the western bank, and prepared to ford the river, but Frodo stood in his saddle and defied them. Three of the Riders rode out into the Bruinen, but at that moment the river was raised into a "plumed cavalry of waves". The other six Riders, who had remained on the western shore, were now driven into the river by Glorfindel, Aragorn, and the other hobbits, each wielding a flaming brand taken from the fire they had kindled. The raging torrent of the river swept the Riders away, and their terrible cries were drowned. Safe at last, Frodo collapsed.
- The River Hoarwell -- Mitheithel in the tongue of Elves -- draining from the Ettenmoors. In the distance, the Loudwater, or Bruinen, could also be seen. The two rivers converged to the south of the Trollshaws, becoming the Greyflood (Gwathló to the Elves).
- A stone bridge of three arches over the River Hoarwell, probably constructed by the Men of Arnor or the Men of Rhudaur.
- An emerald. The Last Bridge was not held against the Ring-bearer because of the heroism of Glorfindel, an elf of Rivendell, who had been dispatched to seek for Frodo. Glorfindel arrived at the Last Bridge to find three Nazgûl there, but was able to drive them off, leaving a beryl on the bridge as a sign to Aragorn.
- The ruins of Rhudaur, one of the three successor kingdoms that rose from the breakup of Arnor.
- Indeed, the Trollshaws are a confusing region to navigate. This explorer had a difficult time tracing the path that Aragorn led the hobbits upon; many of the locations mentioned in this installment are best guesses or deliberate approximations!
- This saddle is difficult to identify and certainly impossible to reach. It should lay to the northwest of the narrow valley leading to the Glade of the Stone-trolls. There are undoubtedly some heights in the area that are suitable candidates, but this explorer is not skilled enough a climber to reach them! The hobbits were lucky indeed to have such a guide as Aragorn.
- It was in this cave that the elf-blades Glamdring, Orcrist, and Sting were discovered and claimed by Gandalf, Thorin, and Bilbo, respectively.
- The trolls Bert, Tom, and Bill: the very three villains that Bilbo and Thorin's company encountered on the Quest of Erebor. Bilbo's cunning and Gandalf's fortuitous arrival led to the trolls' current state. Aragorn knew the story well, of course, and pointed out a bird's nest behind the ear of one of the trolls to reassure the hobbits of their harmlessness.
- The Bruinen, or the Loudwater, flowed from the Misty Mountains, through Rivendell, and eventually joined the Greyflood. The Bruinen was crossable only at its ford near Rivendell, and the Ford was known as the Edge of the Wild. Elrond of Rivendell had some control over the waters of the river, and it was his influence (with Gandalf's assistance) that caused the river to flood, washing away the Ringwraiths.