Mari spends time with Dr. Gilbert while he hypothesizes about the Earth's magnetism. Meanwhile, Waka and her brother search Mr. Hayase's lab for signs of Mari.
It's possible that Dr. Hayase's 
disappearance has something to do with this book, too.
Es posible que la desaparición
del Dr. Hayase
O desaparecimento do Dr. Hayase
também pode ter a ver com este livro.