In the Suits and Silencers Universe, the tourist-facing Seattle Underground only represents a small portion of what's left beneath the city. Kane describes the public version as, "three or four moldy basements deemed safe enough for tours." Beyond those areas is an unstable and constantly shifting network of buried streets, illegal basements, maintenance corridors, tunnels, old storefronts, cave-ins, and semi-flooded passages. Some parts of The Underground are heavily impacted by the tides.

Some sections are effectively neighborhoods. Old storefronts operating in the basements and sub-basements of buildings above have been reclaimed. The population is improvised and improvising: homeless residents, criminals, dockworkers, smugglers, tradespeople, fugitives, and those who are comfortably at home both above and below ground.

Bits and pieces of the Underground have been occupied since Prohibition, according to Quinten. Sometimes, occupants have deliberately knocked through walls to open previously isolated spaces. Earthquake damage has accidentally opened, and sometimes closed, other routes.

• Housing
• Informal commerce
• Smuggling
• Food service
• Bars
• Hiding Places
• Illicit medical and dental work
• Document forgery
• Temporary shelter
• Transportation
• Storage

• Keep Me Coveted
• Keep Me Cuffed