Orphans -- Juvenile fiction. Robots -- Juvenile fiction. Rockets (Aeronautics) -- Juvenile fiction. Extraterrestrial beings -- Juvenile fiction. Human-alien encounters -- Juvenile fiction.

Princesses -- Juvenile fiction. Impersonation -- Juvenile fiction. Kidnapping -- Juvenile fiction. Extraterrestrial beings -- Juvenile fiction. Human-alien encounters -- Juvenile fiction.

Xenomorphs (Fictitious characters) -- Juvenile fiction. Extraterrestrial beings -- Juvenile fiction. Human-alien encounters -- Juvenile fiction. Twins -- Juvenile fiction. Space colonies -- Juvenile fiction.

Human-alien encounters -- Juvenile fiction. Kidnapping -- Juvenile fiction. Space warfare -- Juvenile fiction. Princesses -- Fiction. Impersonation -- Fiction.

Virtual reality -- Juvenile fiction. Artificial intelligence -- Juvenile fiction. Dystopias -- Juvenile fiction. Human beings -- Juvenile fiction. Computer systems -- Juvenile fiction.

Cryptographers -- Fiction Human beings -- Origin -- Fiction Spain -- Fiction. Langdon, Robert (Fictitious character) -- Fiction

Fairy tales. Diplomacy -- Fiction. Spies -- Fiction. Self-esteem -- Fiction. Nature -- Effect of human beings on -- Fiction.

High school students -- Juvenile fiction. High school athletes -- Juvenile fiction. Extraterrestrial beings -- Juvenile fiction. Human-alien encounters -- Juvenile fiction.

Extraterrestrial beings -- Fiction. Life on other planets -- Fiction. Human-alien encounters -- Fiction. Science fiction.

Life -- Juvenile fiction. Conduct of life -- Juvenile fiction. God -- Juvenile fiction. Turtles -- Juvenile fiction. Nature -- Effect of human beings on -- Juvenile fiction.

Impersonation -- Juvenile fiction. Princesses -- Juvenile fiction. Mistaken identity -- Juvenile fiction. Arranged marriage -- Juvenile fiction. Kidnapping -- Juvenile fiction.

Langdon, Robert (Fictitious character) -- Fiction. Cryptographers -- Fiction. Human beings -- Origin -- Fiction. Spain -- Fiction.