In America's heartland Steve and Geoff explore the most inaccessible corners of the strewnfield in Homestead, Iowa, where numerous large meteorites fell in 1875. The Hydratrek "Rockhound" returns, and the guys go marine as they use it to motor up and down the Iowa River. Geoff and Steve have an argument about a strange rock, and then make a stop at their secret Alpha Site in Kansas, where Steve unveils his most bizarre meteorite hunting invention yet.