Themis: Uh... There's a small service charge.
After Batman and Zatanna interrogate Medusa, the boatman (Charon?) asks for a "service charge." Batman reaches into his utility belt and pulls out two coins. In ancient Greece it was believed that when a person died they had to be put on the pyre or buried with two coins covering their eyes. This would act as payment to the boatman so that they may cross the River Styx to the land of Hades. If they did not have the two coins, they would wander the shores of the River Styx blind, deaf, and mute.