# 490d C418 — Flood-boundary closure and obstruction of the 2K profile

24 September 2026. Step 5 of 10 in the C414–C423 authorization.

The person profile extends to a **fifth2K station only by retaining different Flood boundary labels**: SP close3299 maps to MT start2241.

| SP Gear3 boundary | MT Gear1 boundary | Difference |
|---|---|---:|
|Start3300|Start2241|1059|
|Start3300|Close2240|1060|
|Close3299|Start2241|1058|
|Close3299|Close2240|1059|

Using that explicit close/start station, both five-station columns have the same ordered partition: Noah birth→Shem birth500; Shem birth→selected Flood boundary100; boundary→Noah death350; Noah death→Shem death150. The total remains1100. The selected boundary is600 after Noah birth and500 before Shem death in both columns.

This does not translate an entire Flood year. Applying−1058 to SP start3300 gives2242, which is the MT Gear2 close; applying it to SP close3299 gives2241, the MT Gear1 start. These are sourced coordinates with different roles and Gears, not one same-Gear MT Flood interval.

The bounded control releases only event Gear while retaining the selected traditions and variants. All36 start/close/Gear combinations were examined. All18 same-boundary comparisons have odd differences and therefore cannot equal1058. Three mixed-boundary comparisons do: selected SPcloseG3→MTstartG1, SPstartG3→MTcloseG2, and SPstartG2→MTcloseG1. Only the first retains both person-profile Gears. Even Gear changes cannot remove the odd same-boundary offset.

The SP minus-one belongs to the person companion rail; Flood close is an independent event boundary. Treating it as a universal shift would erase exactly the distinction this result exposes. Both valid500/100 and502/98 source modes remain available; this fixed profile uses the former partition and does not revoke the latter.

## Verification and limits

23 main checks and 15 frozen-input/predecessor authentication checks passed. A second main replay produced byte-identical DATA/RESULTS. These checks and the source interpretation were performed by the root agent; no new independent-agent review is claimed. All frozen originals and standing controls remain unchanged. Verification counts are not independent-witness counts.

A source-coordinate image is not automatically the same event, Gear or modal binding. The18 event controls do not enlarge person Gear scope or establish a general negative result outside their fixed variants.

Mirror/529 focus: K=529, E=25/23, P=70/69. Global paired Mirror January AD1; local junction January AD2; no civil year zero. Regular Gears are Noah/Shem/Flood only. SP minus-one person companions remain local to SP Noah/Shem; Flood close is a separate boundary. No upstream/cumulative Gear, new endpoint or phase, fitted anchor, global axis, primer reopening, canonical or graph edit. Capture now; canonize later. Source identity, context, modal binding, generated coordinates and phase ancestry stay distinct.

## Decision after this result

**C419, proposed and unexecuted:** Test the five established2K station pairs against the existing17K cumulative Shem/Flood joins and the already admitted Mirror corner exchanges, using only the frozen cumulative source register and no fitted new axis.

The source profile is now exact and boundary-qualified. The Mirror focus requires testing whether it actually rejoins the existing17K construction before pursuing further harmonic relations.