Subject(s): Code and cipher stories. | Children's stories. | Wills -- Fiction. | Mystery fiction. | Scavenger hunts -- Fiction. | Family secrets -- Fiction. | Orphans -- Fiction. | Clues -- Fiction. | Adventure fiction. | Brothers and sisters -- Fiction. | Children's stories. | Siblings -- Fiction. | Family life -- Fiction. | Mystery fiction. | Adventure fiction. | Vienna (Austria) -- Fiction. | Austria -- Vienna. | Code and cipher stories. | Children's stories. | Action and adventure fiction. | Detective and mystery stories -- Juvenile fiction. | Fiction. | Juvenile works. | Adventure fiction.