Henry Miller fixes broken systems for a living—right up until Silicon Valley fires him for being the only one who'd say the code was rotten. Then he picks up a stranger's coin in a dive bar, and wakes in the mud of sixth-century Britain, fifteen hundred years from everything he knows.He has a plan. He always has a plan. With the accumulated knowledge of the modern world in his head, he'll end the hunger, clean the water, drag these people out of the dark—and finally build something...