Just as that had been said, an elven war horn echoed from behind them, and the troop of elven riders clattered across the bridge.

"Close ranks!" Thorin barked out to the other dwarves in Khuzdul, grabbing Bilbo and pulling the hobbit into the middle of the circle the dwarves had formed, to protect him.
The riders circled around the dwarves, though seemed to pay them little heed at first.

"Mithrandir!" it was Gandalf who Elrond greeted first as he dismounted from his horse. "What brings you here to Rivendell?" his eyes settled on Bane and Serena and he greeted them as well. "I did not look to see you here at this time."