Sweat stings the eyes of archaeologist Sergio Gómez as he chips away the last vestiges of rock in the swelteringly hot tunnel. The dirt falls away, and he begins to see the outlines of some kind of structure in the subterranean gloom. He’s close to uncovering a secret that he’s been seeking to reveal for three decades – and one that could change our view of history.
Gómez was excavating a tunnel that had been discovered some 13 years earlier underneath the Temple of the Plumed Serpent. The huge structure is located in Teotihuacán, an ancient city that lies just north of Mexico City. Fascinatingly, the tunnel contains the remains of a shadowy pre-Aztec civilization.