Kate notices a change in Emilico. Upon reading Emilico's notebook, she tries something to help her, but Emilico vanishes after learning a secret. Kate enlists John in finding her and then shares the secret with the others, but can they thwart Edward?
Is it because if we knew
about soot sickness
Denn wüssten wir von der Rußkrankheit,
¿Es porque si supiéramos
de la enfermedad del hollín
¿Será porque si supiéramos 
de la enfermedad
car s’ils connaissaient le mal de suie,
Forse perché se sapessimo
 del morbo della fuliggine,
Porque, se soubéssemos
sobre a doença da fuligem