The Eagle Dagger was a valuable Aztec artifact discovered in Mexico during the 1930s.
Marcus Brody learned that shady collector Dr. Victor Van Loon was close to finding the dagger and asked Indiana Jones to find it first. Indy arrived at the dig site and distracted Van Loon by pretending to be rummaging through his storage tent. Once inside the ancient caverns, Indy had to dig through numerous piles of rubble until he eventually found the Eagle Dagger.
Van Loon admitted his defeat, yet warned Indy that they would meet again.