Heeding Saeril's advice, Kili stayed near the back of the line with Fili as he often did. Leaving Rivendell so soon was disheartening, but he knew better than to voice his thoughts. Thorin was in charge, after all. 
Still somewhat groggy, Kili rubbed at his right eye to clear it, then took notice of Bilbo looking towards Rivendell as well. Poor Bilbo. Rivendell had the comforts of home he was accustomed to, and now they were back on the road for a grueling trek.

"Master Baggins, I suggest you keep up." Thorin reminded him, then looked towards the sky with a frown. A storm would soon be upon them. "This way." They hiked for a length of time, across the valley and through the woods until they reached the mountains. The path became narrower and lead upwards, and the rain had already begun to fall. A few dwarves mumbled their concern about such a route, and Bilbo stayed as far away from the ledge as he could.

Even Kili felt a bit unsettled by this. The rain was heavy and made it difficult to see. Following by Fili's example, he put up his hood in an attempt to keep the rain out of his eyes, but it was nearly impossible to achieve this. 

As Bilbo walked, the rock beneath his feet suddenly gave way, and he was seconds from falling. Dwalin caught him by the arm and hoisted him back to safety. "We must find shelter!" Thorin shouted back to them, right as a massive boulder hurtled through the air, hitting the mountaintop ahead of them.