Spots 
Wealthy merchant William W. Kolderup outbids his rival J. R. Taskinar for ownership of Spencer Island in the Pacific Ocean. The bidding reaches four million dollars for an uninhabited rock. Kolderup secures the land purely to demonstrate his financial supremacy over Taskinar.
Godfrey Morgan resides in luxury as Kolderup's nephew, engaged to his charming cousin Phina Hollaney. Unwilling to settle immediately into domestic routine, Godfrey asks for permission to travel the world by sea. Kolderup agrees to fund a voyage across the Pacific Ocean.
Professor Tartelett, a fastidious instructor of dancing and social etiquette, receives instructions to accompany Godfrey on the voyage. Tartelett despises bodily hardship and fears ocean turbulence. He reluctantly boards the steamship Dream to preserve his pupil's manners at sea.
Captain Turpote takes command of the Dream as it leaves San Francisco harbor behind. Godfrey enjoys the freedom of maritime life while Tartelett suffers severe seasickness in his cabin. Ocean currents carry the ship deep into remote waters toward the Polynesian archipelago.
Heavy darkness and roaring waves engulf the Dream in the middle of the night. Confusion spreads across the deck as the ship collides with unseen rocks and founders. Godfrey and Tartelett get cast into the raging sea amidst crashing waves and splintered timber.
Godfrey washes ashore at daybreak and discovers Tartelett shivering on the sandy beach. No sign of the ship or crew remains along the desolate coastline. Realizing they are isolated from civilization, the two survivors take stock of their meager possessions.
Exploration of the interior leads Godfrey to a colossal hollow tree trunk near a freshwater stream. Naming the giant specimen Will-Tree, the castaways establish their primary base inside its spacious interior. The natural fortress protects them from wind and rain.
Godfrey learns to hunt, gather edible plants, and build tools out of wood and stone. Tartelett bemoans the complete absence of French cuisine, clean linens, and civilized conversation. Survival forces Godfrey to take charge of all physical labor.
Godfrey constructs rudimentary furniture and a hearth inside Will-Tree using driftwood and clay. Fire-making success brings warmth and cooked meals to the camp. Tartelett slowly adapts to eating wild game while keeping track of passing calendar days.
Tartelett insists on practicing dance steps and practicing proper posture on the forest floor. Godfrey finds humor in his companion's refusal to abandon urban formality. The dancing master attempts to teach wilderness animals proper deportment.
Distant smoke alerts Godfrey to visitors landing on another part of the island shore. Watching from high foliage, he witnesses a confrontation between rival landing parties. Godfrey fires his gun to intervene and rescues a native captive from danger.
The rescued native joins Godfrey and Tartelett, receiving the name Carefinotu. Carefinotu brings valuable practical skills in fishing, tracking, and foraging for indigenous roots. The trio forms a cooperative routine inside Will-Tree.
Lions, tigers, and crocodiles suddenly roam the island landscape, defying all geographical logic for a Pacific islet. Godfrey and Carefinotu construct defensive barricades around Will-Tree. The presence of fierce apex predators turns daily survival into a constant battle.
Wild animals surround Will-Tree during a dark storm, attempting to breach the timber stronghold. Godfrey, Tartelett, and Carefinotu fight back with fire, spears, and rifle shots. The siege tests their endurance to the absolute breaking point.
William W. Kolderup arrives on a steamship to end the experiment and reveal the truth. Kolderup had purchased Spencer Island, staged the shipwreck, hired actors, and imported wild beasts to build Godfrey's character. Godfrey returns home educated in resilience, ready to marry Phina.
A wealthy youth learns self-reliance when a staged shipwreck leaves him stranded on a Pacific island.