Related Clues:

• Mythological river of the underworld
• 'Kilroy Was Here' group
• Group that sang the line 'I'm Kilroy!'
• A pigpen across a hellish river
• "Kilroy Was Here" group
• Group that sang the line "I'm Kilroy!"
• Water below doesn't move audibly
• Soundly secures spirits transported over this
• 'One more river' — and every character can follow 17
• One of the rivers of Hades
• River of hell
• River crossed at death
• "Come Sail Away" band
• Final crossing?
• Runner down under?