Aetheric Mechanics is set in an alternate history March 1907, where steampunk technology is advanced far beyond the technology of the modern real world, including two-way television communications, air- and spacecraft powered by reactionless drives, and large combat mecha. The British Empire (which in this setting, includes realms on other planets) is engaged in a war against Ruritania. The war is not going favourably for Britain; however, the British government is covering up just how badly the war is going, including the fact that Ruritania is preparing an invasion of Britain.