In Memoriam (released as Missing: Since January in the US) is an adventure video game for Windows and Macintosh. It uses alternate reality-style gameplay, in which the player receives e-mails from other in-game characters, including the game's main antagonist. The player needs to find information and clues to the games' puzzles on the Internet, both from real websites, and from specially-created websites that have been mixed in with other "real-world" domains.