The system's countdown warning that Emberus would destroy the ninth floor in three minutes.
The moment Samantha came down burning, the warning went out: Emberus will destroy the ninth floor in three minutes.
The countdown structured everything that followed — Elle and Donut picking over the last two items on the table, Bautista's confession and his warning about Kimaris, Mordecai sitting in the dirt with a bottle until only a minute remained, and finally Carl and Donut walking into the stairwell together as Larracos emptied.
The countdown that compresses every remaining goodbye on the ninth floor into three minutes.