As she was dying of a brain tumor in 1996, Dorothy Holm puzzled her grandchildren by writing out strings of seemingly random uppercase letters on index cards, the Sydney Morning Herald reports. Nearly twenty years later, her granddaughter Janna was determined to discover what she thought might have been a secret code, so she submitted photographs of an index card to the riddle-solving website Ask.MetaFilter.com. Within minutes, one user discovered that Dorothy’s seemingly random letters were actually shorthand for prayers: “OFWAIHHBTN… Our Father who art in Heaven, hallowed be thy name...” Dorothy’s family is surprised and relieved to know, after all these years, what she was thinking of in those last few weeks while she was unable to speak. And although some of the letters appear to be personal prayers that may never be solved, knowing at least what the code stands for has brought them peace. "I don't care if a little bit of it never gets solved," Janna said, according to SMH. "It's OK to have a little bit of mystery."