The character Ms. Ma is based on Miss Marple, a character in novels and short stories written by Agatha Christie. The two characters share sharp observational skills, insight into human nature, and a fondness for knitting. However, the Miss Marple of the books was never accused of a crime herself, never married nor had children, and is notably older than the character of Ms. Ma.
The mystery plots taking place around Rainbow Village are an amalgamation of various Agatha Christie novels: The Moving Finger (anonymous notes and supposed suicide), The Mirror Crack'd from Side to Side (a murder at the home of an actress), A Murder Is Announced (a party game interrupted by murder), and The Body in the Library (a dead body left at a location to frame someone else). The main story that makes up the background of the entire series (a case of false conviction being investigated years later) is loosely based on Nemesis, and shares a similar method of murder, but the motives and relationships between characters have been changed. Additionally, the organization called "Bertram" is an allusion to the title At Bertram's Hotel and the criminal gang that operated therein.