The way the creature held Ambrose by the throat was as if it knew how much Ambrose meant to Caleb.  It held him as if it had the best bargaining chip and knew that Caleb wouldn't attack as long as Caleb knew how much danger Ambrose was in.  This put Caleb in a spot he didn't like to be in.  He had to do what was asked of him for fear of the creature slitting Ambrose's throat with its claws.  Caleb didn't move, his eyes never left the face of the creature.  He exuded strength in the moment when others would probably exude fear.  He wanted the creature to know that he wasn't afraid of it and if he tried anything he wouldn't hesitate.  He watched Ambrose closely and realized he was silent which meant he had accepted his role as the hostage in this situation.  Caleb listened to the monster as he requested their help in retrieving a staff.

"Let me get this straight," Caleb began, "you want us to waltz in there, take the staff, and return it to you and in exchange, you'll help us in our mission?" The creature began to touch Ambrose in ways that really irked Caleb to the point that Caleb just wanted this meeting to be over and if the creature looked carefully he would be able to see the anger in Caleb's eyes and the fact that Caleb had clenched his fist.

Caleb took a moment to contemplate it before nodding.  "Let him go and I will help you, but first I need to know your name."  He didn't know what this staff meant to this creature.  He didn't know what he would be handing over willingly to this monster.  Knowing the creature's name would hopefully give him some insight as to how he'd handle the situation.  Perhaps he could ask questions to the locals to figure out what the creature was.