Step into the thrilling world of DC Comics with Detective Comics #639, a key issue that is a must-have for any comic book collector. Published in December 1991, this gem is a valuable addition to your collection, offering a glimpse into the iconic DC universe. What makes this edition even more special is the inclusion of a Sonic the Hedgehog insert, adding an extra layer of excitement for fans of both franchises. Dive into the pages of this classic comic and immerse yourself in the captivating storytelling and stunning artwork. Don't miss the chance to own this collectible piece of comic book history - grab your copy of Detective Comics #639 now!