The dwarves all looked to and fro in surprise, as if they had all only just realised that the hobbit wasn't with them.
"Well, I thought he was with Dori!" cried one of the dwarves. Though at that shout Dori looked rather offended. 
"Don't blame me, I'm not his babysitter!" he protested.

Meanwhile, Bilbo had just managed to escape Gollum and the goblins by turning invisible when wearing the ring he had found on the floor in Gollum's cave.