From sea to shining sea, the United States is home to some of the most perplexing mysteries on the planet; strange spots cover a vast stretch of desert near the Grand Canyon; a Los Angeles water reservoir unexpectedly turns black. This episode is a mashup of segments from S03E12, S03E08, S02E02, S03E01 and others.

Strange satellite images fuel new investigations into some mysteries of the ancient world; mysterious markings in the Peruvian desert; a secret structure buried near the ancient city of Petra; an abandoned fortress in an arid wasteland. This episode is a mashup of segments from S01E02, S02E02, S03E03, and others.