After Bilbo and the Dwarves had left Rivendell, in secret and with no bidding from Gandalf, they began their ascent into the mountains and found the sky laden with heavy clouds. Bilbo was thinking of the sights and smells of Rivendell, and trailed reluctantly at the back of the party.
"Master Baggins," snapped Thorin Oakenshield, "you had best keep up."
Such impatience in his voice. Such disgust. Bilbo patted his vest to make sure his new handkerchief (Elven-made and softer than silk, for the Elves had sensitive noses) was still tucked in the pocket and walked on, his eyes cast downward to hide his embarrassment.
Bofur patted Bilbo's shoulder as he strode past.
"It's only the smell of Elf in the air, laddie," he said. "He'll be in a cheerier mood when we've left sight of Rivendell."
"Seems he's actually allergic to the hospitality of Elves," Bilbo muttered.
"I would have no trouble believing it," said Bofur. He tweaked Bilbo's ear — something Bilbo was sure he would not have done had there not been almost four inches of height difference between them — and pushed on, leaving Bilbo at the back of the company.
They climbed steadily higher into the mountains, until the winding paths through knotted grass and flowers became harsh stone outcroppings which were slick with mist and, eventually, ice. Several hours in, Kili slipped and scraped both his knees, and would have dropped right off the path had Thorin not seized the back of his tunic in time. The Dwarf leader dropped his nephew none-too-gently to solid ground and gave him a look of utter contempt before calling the company to move on — Bilbo felt a bit better then. At least he was not the only one at the brunt of Thorin's wrath.
Clouds were gathering on the horizon in an ominous leaden sheet, and a cold wind ruffled Bilbo's hair — it was going to rain, heavily and soon. Thunder rumbled in the distance.
What would Thorin Oakenshield have done, he wondered, if it had been him, and not Kili, who had slipped and fallen off the mountain? Let him plunge to his death, most likely. Bilbo dabbed his streaming nose with his handkerchief. They're quite a merry gathering, Gandalf had said. Merry, his ass. Except for Fili and Kili, and perhaps Bofur, the Dwarves had nothing but contempt for him. To them, Hobbits were like children. Or hamsters. Dwarves cared about their own kind, but certainly not for Hobbits. Bilbo remembered the conversation he had overheard between Thorin and Gandalf:
I cannot guarantee his safety.
Understood.
Nor will I be responsible for his fate.
The rain had begun, and with it a fierce wind. Bilbo thought nothing of it until a roll of thunder crashed down upon the mountain, a sound louder than any he had heard before, a sound that made the earth shake and boulders dislodge themselves from the edge of the path.
"By the gods, what a storm!" said Dwalin. His voice was ripped away by the wind.
"We must find shelter!" roared Thorin. "Stay together!" He turned briefly to view his company, and Bilbo stopped short — was that fear in the Dwarf leader's eyes?
Suddenly there was a great crunching of rock upon rock and the entire mountainside on which they stood lurched up and down. Bilbo lost his balance and went sprawling across the stone. He would have gone over the edge, but his fingers found a protrusion in the rock and he held on to it with all his strength, spluttering against the deluge of rainwater and grit that washed over his face. Over the roar of the storm and the stone he heard one of the Dwarves shout something in a voice choked with panic.
"Storm — storm giants! It's a fucking battle!"
Bilbo was not normally one for profanity but in this case he found himself agreeing with whichever Dwarf had spoken. The rock stilled for a moment, enough that Bilbo was able to pull himself to his knees, and then a shattering crack rent the air as the mountain beneath his feet began to split in two. He leapt backward.
"No — no — Fili!" Kili's voice made him look up, and he caught a glimpse of Fili and Kili at the edge of the widening gap, grasping desperately at each others' arms. A flash of lightning illuminated the stark terror on Fili's face before he was swept away from his brother. Kili slid backwards down the rock face toward Bilbo, weeping earnestly as he grasped at pebbles and stones.
Having braced himself against a fold in the cliff, Bilbo looked wildly around himself; he was stranded on a ledge that was moving up and down with a steady rhythm, and beside him were Kili, Dwalin, Bofur, and two or three other Dwarves whose faces he couldn't see in the torrent. The rest of the company, including Thorin, had been borne away by the storm. Bilbo opened his mouth to call to the Dwarves, but his words trailed off in a scream as he lost his foothold and found himself sliding backwards towards the edge.
"Bilbo!" Bofur hurled himself across the stone and seized the Hobbit's arm. It took all his strength to stop Bilbo's progress, and he almost let go on his own when a gust of wind carried his hat off his head.
"Thank you, Bofur," said Bilbo dazedly, but Bofur didn't reply — his eyes were fixed upon something in front of them, a sheen of glassy horror on his face, and when Bilbo looked up he immediately understood why. A massive wall of rock, the size of a house, was thundering towards them, and they were trapped against the side of a mountain. In the shock of the moment, in knowing he was about to die, Bilbo looked to his right and saw, perhaps twenty feet away on a small ledge, the rest of the Dwarven company. A strip of lightening threw their faces into white relief — Fili with his hand half-outstretched, his mouth open in horror; Thorin dropped his sword and all but leapt off the cliff toward them, howling the names of his company.
"Kili! Dwalin! Bofur! Halfling!"
He locked eyes with Bilbo and there was terrible regret in his gaze, but there was no time for Bilbo to react or even think, because at that instant the mountain crashed into his ledge with a sound to wake all the dragons of the First Age, and all went dark.