The FBI laboratories are used daily by the Federal Bureau of Investigation in solving crimes and protecting the safety of our nation and our homes. Young Tommy is being taken on a tour of the FBI Laboratory, and because he has so many questions, its decided that to help him understand, they will reconstruct an imaginary crime, then as they go through the various laboratories, Tommy can try to work out the solution from what they see. Tommy chooses to track a couple of murderers, so they start at the first point of call - blood analysis.