Ken and Sandy join an archaeological expedition in southern New Jersey near the Delaware Bay. All they expect to do is dig trenches for three or four days and not get involved in any mysteries. However, when they join the expedition, they learn that several members of the expedition have heard galloping hoof beats at night. The local people have also heard these hoof beats of what they refer to as the ghost of the galloping horse. Captain Kidd was rumored to have buried treasure in the area of the expedition, and the treasure was protected by a galloping horse. During prohibition time, the galloping ghost was heard and scared the superstitious locals away. The hoof beats were most likely produced by rum-runners who didn't want people snooping around. However, not only is there a ghost, but someone is spying on the expedition. Whoever it is, they are ruthless and will stop at nothing to sabotage the expedition.