Black Rain (ブラックレイン, Burakkurein) is the 18th chapter of Clockwork Planet manga series.
Marie and Vainney break into the residence of gorvernor Mirkatsu Muroi, of Grid Mie, to interrogate him. They question him about the weapon they found in the factory complex, and he reveals that it was originally a deterrent against the government from purging the grid just as it purged Grid Shiga to cover up illegal electromagnetic technology research. He claims that the weapon was intended to remain inactive, but after Marie confirms that it is, indeed, combat-ready, he realizes that the government has now activated the weapon themselves to give them an enemy to defeat so that they may regain their reputation that had been tarnished by Marie, and declares that it is all her fault for her exposé. Outside, Marie begins weeping under the rain that she caused a war and she's helpless to stop it. Naoto and RyuZU suddenly emerge from a nearby manhole cover, complaining about the rain.