A group of teenagers discover the dog-tags of a Navy Petty Officer whose half-eaten body is later found in a park but Ducky soon discovers that the Petty Officer died after being stabbed in the chest and he was already dead before the bear started eating him. The team soon discover that the victim was with a woman who has also disappeared but the case descends into a nightmare when further investigation reveals that the deaths in the park which were all ruled accidental or natural might not be those after all which has Gibbs fearing the worst: a serial killer is on the loose in the park and is using the deaths to cover up a much worse crime: murder.