Batman #81

When the reformed Harvey Dent tries to prevent a robbery, he is caught in an explosion and reverts to Two-Face. He embarks on a new crime spree, and Batman and Robin deduce that Two-Face is going after people who commonly show two faces to the world. At a ceremony making Bruce Wayne honorary chief of a local tribe, Batman and Robin are trapped by Two-Face and strapped to a giant coin. Two-Face flips the coin over a bed of spikes, and though the gimmick is rigged to land face down, the dynamic duo manages to create a magnetic field and flip the coin so that they land safely.