He crossed the shallow river and advanced boldly toward the Pyramid of the Sun.

His reason told him that there were no such things as ghosts, but it told him also that Mexican peons were likely to believe in them.
Hence it was probable that he would be safer about the Pyramid than far from it.

The country bade fair to become too rough for night traveling and he would stop there a while, refreshing his strength.
Although the sun was setting, the color of the skies promised a bright night, and Ned approached boldly.

As usual his superstitious fears became weaker as he approached the objects that had called them into existence.

But before he reached the pyramids he found that he was among many ruins.