Mari and Waka plan on making a cake for their friend, but plans fall apart when Mari opens a mysterious book that sends her flying back in time where she ends up crossing paths with William Gilbert.

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.

An afternoon following a school lesson on Ben Franklin leads to Mari meeting the man himself, helping with the kite experiment, and discussing future appliance innovations.

Mari meets up with an unexpected guest of Alessandro Volta and learns a little more about her father's whereabouts.

Waka's wish to travel back in time is granted, but things don't go quite the way she had planned.

While Waka is still stuck in 19th century London, she learns a valuable lesson about dedication and overcoming failure.

Mari takes a break from fretting about midterm grades to witness an electromagnet demonstration inspire a revolution in communications technology.

A day at the beach takes an unexpected turn when Dr. Hayase's former business partners arrive.

Mari has a chance encounter with her father once again and learns more about his motivations for traveling back in time.

Mari defies her mother and travels back in time once again. Meanwhile, trouble is brewing back at Hayase's lab.

After being caught red-handed at Hayase's lab, Mari is forced to make a difficult decision that could greatly impact her father's future.

A rift appears in space-time, trapping Mari, Mikage, and Dr. Hayase in Edison's warehouse. With Hayase's lab experiencing a meltdown, will the trio make it back to the future?