The Fifth Hargreeves

When you walked into Max's buffet, you looked around in surprise. There were many people in the buffet, but they were all one person: a Hargreeves Fifth. One of the Fifths approached you and invited you to sit at the table. He said:

It's not often that anyone other than me comes by. By the way, our menu only includes peanut butter and marshmallow sandwiches, and our drinks are limited to coffee and strong whiskey. Ready to order?

The rest of the Fifths have also taken notice of you.