Harry Potter and the Mysterious Thief part I is a fan game which takes place in Harry Potter universe. You play as Harry Potter, who is now working as an Auror. Harry has to work on the Mysterious Thief's case together with Draco Malfoy and Ron Weasley. During the investigation he develops romantic feelings towards his former school enemy - Draco.
Since this is the first part there is only one ending, but it is important how you will get to it.
Three years passed after Hogwarts. Harry is working as an Auror and he has to team up with Draco Malfoy to work on the Mysterious Thiefs case.