This article is about the improvised explosive device. You may be looking for the Co-op mission.
"The surviving Royalists are going to attempt an attack on Napoleon. The centerpiece is a giant improvised explosive device, lovingly known as the 'Machine Infernale'."
Bishop, 2014.[src]
Infernal Machine

The Infernal Machine

The Infernal Machine (French: Machine Infernale) was an improvised explosive device meant to be used by the Royalists, led by François-Joseph Carbon, to assassinate Napoleon Bonaparte on his way to the opera on 24 December 1800. The Royalist snipers meant to shoot the device once Napoleon neared it were killed by Assassins.