The Fourth Nail was an artifact sought by Indiana Jones. The Nail was said to be stolen by Gypsies before the crucifixion of Jesus Christ. The first and second nails were for the hands, and third for the feet, and the fourth to deliver the fatal blow to the heart. The Gypsies believed they were protected by God for stealing the item that would have brought instant death upon His son.
Unlike his search for other Christian artifacts, Indy attempts to keep the Fourth Nail from the hands of artifact collector Ben Ali Ayoob rather than the Nazis.