Architect Houston's rifle attack on Carl the instant the ceasefire lapsed, planned around Stockade's sacrifice.
The moment Phase One Combat engages, Architect Houston jumps to his feet in the The Lemig Castle, his robes flinging back to reveal a horrific bug-like body with six arms, two holding a rifle. He fires as Carl dives; Carl lands against a counter, grabs a bag of cat food, and drops an impact Hob-Lobber before Baroness Victory's twenty-second teleport pulls him out mid-shot.
Carl arrives in the Field Hospital with a hole punched through his shoulder, and reasons that Houston planned all of it — or at least knew what was happening to Commander Stockade and compensated, willingly sacrificing another living, breathing world leader to get a shot at Carl. The bomb failed, since a kill would have produced a message, and Carl regrets going with his Hotlist instead of something bigger. Houston's earlier taunt — that Carl was in mortal danger and didn't realize it — was a warning delivered in plain sight.
The assassination attempt that opens the Faction Wars for Carl personally.