| 1 | CUSTOS-9 announces lockdown. The purge hazard rolls initiative, and the maintenance hatch seals. |
| 2 | Mara Venn shouts the hatch location and throws a smoke canister. A 10-foot burst near the center lane becomes concealed until the start of round 4. |
| 3 | The subdermal anchors in the twins’ necks flash. Vanya warns that the collars are trying to reboot. This foreshadows Scene 2. |
| 4 | A gantry support tears loose. One 10-foot line chosen by the GM becomes difficult terrain and provides standard cover. |
| 5 or Later | Final ignition occurs unless delayed. Any creature still in the cell block faces Chamber Incineration. |