London

“As some of you already know,” he went on, “MEDUSA is an experimental energy weapon from
the Sixty Minutes War. We have known about it for some time—in fact, ever since Valentine found these documents on his trip to America, twenty years ago.”

The projector-screen was flickering with faded diagrams and spidery writing. Father never told me that! Katherine thought

“Of course, these fragmentary plans were not enough to let us reconstruct MEDUSA.” Crome
was saying. “But seven years ago, thanks again to Valentine, we acquired a remarkable piece of OldTech, taken from a long-lost military site in the American desert. It is perhaps the best preserved Ancient computer-core ever discovered, and it is more than that; it is the brain of MEDUSA, the artificial intelligence that once powered this remarkable machine. Thanks to the hard work of Dr Splay and his comrades in B Division, we have at last been able to restore it to working order. Guildspersons, the days when London had to run and hide from other hungry cities are at an end! With MEDUSA at our command we will be able to reduce any one of them to ashes in the blink of an eye!”

Chapter 21: In the Engineerium, Mortal Engines, pg 91/ 152