Ah hah! This chapter is all about the Lullaby. I can basically read the author's mind at this point, did I call it or what about that possibly being important later. Read my last post if you don't know what I mean. Leona owes me a McDonald's chocolate shake.
This chapter takes us back to "the present" I guess, back with Allison on the ship, taking it over. The Lullaby turns out to be an actual lullaby, taught by Capital Sam, Allison sings it over the loudspeaker and puts everyone to sleep. I think this is the first instance in the whole book where something was named what it actually was. Normally you'd expect a lullaby to be named The Baby Muzzler, or Bespeckled Ralph's Aural Pacifier. And then maybe "The Lullaby" would turn out to be a very quiet fax machine.
So after everyone's asleep, Sam climbs aboard through the toilet and Allison asks him where he learned the song. He says that he learned it from someone (possibly a mermaid) named Muirin, who I am mentioning even though I bet (strawberry this time?) that it turns out to not be important.