Little Nemo in Slumberland follows the dreams of Nemo, a young boy whose sleeping imagination transports him into an elaborate fantasy world.

In Slumberland, King Morpheus wants Nemo brought to his court to become a companion to the Princess. Reaching the royal palace, however, is rarely simple. Nemo’s journey is repeatedly interrupted by magical transformations, unusual creatures, enormous cities, moving beds, impossible staircases, and environments that change without warning.

Nemo eventually encounters recurring characters such as Flip, a mischievous cigar-smoking troublemaker whose hat carries the words “Wake Up.” Flip may serve as Nemo’s companion, rival, or the cause of another dream going unexpectedly wrong.

The stories frequently conclude when a frightening, surprising, or uncontrollable event causes Nemo to awaken in his own bed. This repeated movement between fantasy and reality gives the series its distinctive structure.

McCay designed the comic page as part of the dream itself. Panels stretch, shrink, collapse, or change shape as characters move through strange environments. Architecture, color, scale, and perspective contribute directly to the storytelling, allowing the reader to experience the shifting logic of Nemo’s dreams.