An English lord and John Bull, his servant, and a guide shelter from a sandstorm in a pyramid during an African safari.They start to become noisy, but the guide asks them to quiet down in respect for the Pharaoh's daughter who is lying in a coffin somewhere in the pyramid. So, to pass the time, the guide gives out opium. As soon as the nobleman puffs the opium, weird things start to happen. The many other mummies in the pyramid start to come alive. Suddenly the Pharaoh's daughter, Aspicia, comes alive and lays her hand over the nobleman's heart, and the nobleman is transported into the past. He becomes Ta-Hor, an ancient Egyptian man who saves Aspicia from a lion. Ta-Hor and Aspicia fall in love, but she is betrothed to the Nubian king. They run away together and the king chases them. Ta-Hor and Aspicia stop in a fishermen's inn to hide out, and the local fishermen ask them if they want to come on a fishing trip. Aspicia decides to stay behind. Then the Nubian king stops at the inn to rest and finds Aspicia who jumps into the Nile River to escape his guards.
At the bottom of the river, the Spirit of the Nile summons the great rivers of the world to dance for Aspicia, then he tells her that she must stay. When she hears this, she asks for one wish; to bring her back to land. When the fishermen and Ta-Hor arrive back on land, the Nubian king detains Ta-Hor and brings him back to the Pharaoh's palace to be punished for "kidnapping" the princess.
When Aspicia comes back to land, the fishermen bring her back to the palace. She gets there in time to see Ta-Hor sentenced to death by a cobra bite. She explains that if he dies, she dies, and reaches out for the snake to bite her. The Pharaoh pulls her back and grants her permission to marry Ta-Hor, and the Nubian king leaves in a fit of rage, swearing revenge. Everyone starts to celebrate, but as the party reaches its peak, the opium dream ends and Ta-Hor is transformed back into the English lord. As they leave the pyramid, the nobleman looks back at Aspicia's coffin and remembers the love that they shared and still share.