maybe you can have him try to explain the dracula situation. and than be at a loss for what else happened. for gabriel would know more about dracula and what happened during the mission than he, carl does.
also, try to make a quick excuse for the reason why gabriel left the room so abruptly like he did. and apologize to the order about that.
maybe since he doesn't know much, he'll leave the talking of drac to gab later on when the hunter is up to it. also, maybe to calm /distract his nerves, he can either get to bed and do some research while chillin' in bed. and/or go down to the labs on the next floor down to see how everyone else is doing and check out the gadgets. also check on the ones he was working on. maybe he can work on some gadgets he was experimenting with.
note, that carl is a experimenting/inventor and also a friar.