After the Mystery Inc. gang goofed up a case and nabbed an innocent man, they’re forced into early retirement from crime solving. It’s not long however, before their old friend Vincent Van Ghoul needs help and pulls the team right back into action. The gang has unfinished business they must tend to, which involves catching a ghost that previously got away. It all happened one summer while Velma and Freddy where away at camp. Scooby-Doo, Shaggy and Daphne secretly hunted down 12 of the world’s spookiest ghosts but failed to catch the most evil one of them all…the 13th ghost…