Words Across Worlds

Many years ago, Remus Lupin and Lily Evans stumbled upon diaries that mirrored each other and allowed long distance communication. Then Remus fell into another world and met the handsome Sirius Black and his friends. Now they must all go on the run to protect the secrets they know. (From the Casefile on Harry Potter by Draco Malfoy, with bonus annotations by Hermione Granger.)