Blue Madonna: A Carol Reed Mystery is the seventh game in the series. It's summer in Sweden, but Carol knows that with the temperatures, the crime rates will rise. She decides not to remove her detective agency ads from the newspaper and soon enough a new potential customer contacts her. Artist Christina Falk thinks she is being followed and she suspects the 'stalker' has also been in her house. She asks Carol to meet her the next morning, but when Carol arrives at the museum they were supposed to meet at, she learns Christina has committed suicide. Carol decides to investigate this; why would someone ask for a meeting with a private detective and then kill herself immediately after?
Blue Madonna is a point and click adventure set in Norrköping, Sweden, and like the other six games it was created with real photographs with a watercolour effect. Over the years, the amount of watercolour effect has diminished drastically. Each photograph is a node. You can look in all four directions by clicking on directional arrows on the screen and travel from node to node. Using a map, you can travel to different locations that need to be unlocked first, for instance by talking to people or finding addresses in a diary or on a note. An in-game hint system can be accessed via a notebook in the inventory. The game is fully voiced (in English) and has optional subtitles and an optional tutorial.