We all know the story. James woos Lily, they get married and have a child, then get killed by Voldemort, but Lily's love helped her son win the war. But we've also heard that James was a jerk in school, and Lily obviously wasn't a pushover, otherwise she would never have given her life like she did.
So...what happened? What did Moony, Wormtail, and Padfoot do to help dear ol' Prongs get the girl? Something had to happen, because James wouldn't have married Lily unless he had changed at least a bit.
But you can't just focus on one person for seven years; Sirius and Remus and Peter had to have something going on. Something they could tease each other about.
And hey, what Marauder story could be complete without some midnight snacking, run-ins with Severus, and some dangerous shenanigans?