Jennet Plumleaf and Olyvia Ethelinda von Royceston couldn't be more different. But when circumstances find them both stowaways aboard the Fortress Caerhayes, they find themselves bonding over the shared experiences, and the new talents awakening within them.

Bored young squirrel noble Olyvia decides to play a prank, dragging in runaway field mouse Jennet. When things go off the rails, the pair finds themselves ascending on one of the loading platforms into the mysterious flying castle.

Having been discovered as stowaways, the two young girls are thrown into service aboard the Castle, with a rude wake-up call, ruder uniform inspection, and only a lifetime of manual labor to look forward to.

After mopping the seemingly endless floors of the Castle bottom, Jennet and Olyvia finally open up to one another over their first meal.

After the day's work, the two girls return to their tiny quarters, and begin to share more about their pasts.

Another day of mindless labor gives the two girls a lot to think about, and as they date to reach out to one another, as friends now.

Watching the stowaways working non-stop in the depths of the Castle, one of the kitchen staff sees a chance to offer one of them a chance to help him.

Jennet returns to her bunk, confused and overwhelmed by the new job under Princeton, but as she tries to break the news to Olyvia, the young squirrel takes it the worst way possible.

As Olyvia's temper lands her in trouble in the Inner Furnace, its potentially dangerous output attracts the attention of Court Mage Lady Artemis, also known as Devana, an Owl seeking to protect the castle's magical inner workings.

While Jennet works, her new position in the kitchen has not gone unnoticed, as Head Maid Bernadette storms in to give Princeton a piece of her mind.

With Olyvia riding high, and Jennet at an utter low, the two return to their quarters and hash out their hurt and hopeful feelings to make a truly powerful connection to one another.

A nearly fatal mistake in the kitchen reveals that Jennet is illiterate, and an angry Bernadette gets an opportunity to learn what makes the mouse tick, and finds a strangely sympathetic connection to her.

Devana begins Olyvia's training, learning as much as she can about the Squirrel's magical power.