Irkalla takes its name from the Mesopotamian underworld, and the residents who coined it had a sense of humor about their situation. The northern half of old Irving Park — the quiet half, with its historic greystones and tree-lined streets — was absorbed into a Vantage Meridian residential development zone in Year 9. The corporation gutted the buildings, kept the facades, and filled them with climate-controlled Tier 3-4 housing units. From the outside, the greystones look exactly as they did a century ago. From the inside, they are corporate product. The trees were replaced with synthetic equivalents that require no maintenance and produce no allergens. The result is beautiful and completely dead — a museum of a neighborhood, preserved in corporate amber.

The southern half was not so lucky. Too close to the Kennedy Expressway interchange — now a maglev junction called the Switchback — the southern blocks became transit infrastructure. Buildings were demolished or absorbed into the junction's support structure. What remained between the pylons and the maglev tracks became a squatter settlement that calls itself the Understory, home to maintenance workers who service the Switchback and the unofficial economy that feeds them. The Understory is loud, oily, perpetually vibrating from train traffic overhead, and completely invisible to the people riding those trains.

The split between north and south Irkalla is physical and absolute. A corporate security barrier — officially a 'transit safety perimeter' — runs along what used to be Irving Park Road, separating the preserved greystones from the squatter pylons. Crossing requires either a Tier 3+ access credential or knowledge of the seventeen gaps in the barrier that the Understory residents maintain and the corporate security AI pretends not to notice. This arrangement suits everyone: Vantage Meridian gets to report zero unauthorized crossings, the Understory gets to exist, and the barrier gets to be a metaphor for everything wrong with the tier system.

The name stuck because Irkalla, in mythology, was a place you could enter but never leave. The Understory residents appreciate the irony. The Tier 3 residents in the greystones don't get the reference, because their neural interfaces auto-filter cultural content below their engagement profile.