"The Shoebox Project" is written by Lady Jaida and Dorkorific and can be found here or in PDF here. It is a Harry Potter 'fic set during the era of the Marauders; it incorporates all the tantalising hints that JKR has given us about the schooldays of James, Sirius, Remus, and Peter and weaves them into an excellent story that just happens to be a Remus/Sirius slashfic as well. It is regarded as a -5 on the Plotlessness Scale, making it the best-plotted slashfic known to the Department of Bad Slash at this point in time.