Case Closed: Volume 1 by Gosho Aoyama

Ghastly beheadings, bloody murders, and cold-hearted child abductions-

Precocious high school student Jimmy Kudo uses his keen powers of observation and astute intuition to solver mysteries that have left law enforcement officials baffled.

Hot on the trail of a suspect, Jimmy is accosted from behind and fed a strange chemical which physically transforms him into a grade schooler. Taking on the pseudonym Conan Edogawa, he attempts to track down the people who did this to him. But until he discovers a cure for his bizarre condition, Jimmy continues to help the police solver their toughest cases.

Can you crack the case before Conan does?