Bea: Listen to that song. It's heartbreaking.
Kaiwan: Pull the rat's tail, and it will open a door.
Max: Thanks, but no thanks. I'm not going to fall for one of Laoshu's tricks.
Virgil's means of summoning: Max is eating Chinese food with his mom. She opens a fortune cookie to see her fortune, and discovers a message from Virgil for Max. The message was, "You must undo the puzzle that has been undone. Take the portal at the barbershop, Virgil."
Educational Epilogue: The Bianzhong bells
This episode presumably takes place before Zygote's Music; the same tourists are seen at the Great Wall of China here, but were never shown being restored to normal after being de-evolved into gorillas by Zygote.