Steve was too busy looking at his phone, so he fell off of the edge of the Earth, into the underworld.

Fortunately, he found an old wizard who will transport him back up to Earth... the wizard just needs his glasses.

The wizard gives Steve a map, detailing various threats, and where the location of the wizard's glasses are.

But most importantly, the map details where the cell phone towers are, and where Steve can get reception (so Steve can get his fix of Cartographers' Guild maps.)