Talk to Noodle at the Iceberg. He will tell you that it is time to pay your debt to the Fettucine Mafia and will teleport you to a seemingly innocent iceberg. Search the cracked rock and you will find that you are able to fit through it. You will come out into a dimly lit chamber filled with Macaroni penguins. Go to the far end and talk to the bouncer. Tell him that Noodle sent you and he will allow you to see "the Boss".