If you want to catch up on NBC’s Heroes before Monday’s season finale, Sci-Fi kicks off an all-day marathon this morning at 9 Eastern. TV Squad points out that, for some strange reason, the episodes aren’t being shown in chronological order (for instance, “Homecoming” airs at 9 a.m., and the pilot at 11 p.m.). So, maybe this marathon isn’t designed for the new viewer, but for the dedicated fan who missed an episode or two.