The twins have a bit of a mental checklist, when it comes to the crew members, and who gets what amount of alcohol.

Having never met River before, and not knowing of her, Murphy cares about only one thing; she's apparently Irish, and so she gets a full serving poured into her beaker, albeit of the weaker stuff.

He's not sure how old she is, after all.

"There ya are, miss. Drink up."