A 25th-century woman wakes up in more than 800 years and discovers that she is only an electronic copy of the deceased personality in the virtually immortal composite body of a personal cybernetic android, Stuck in an interstellar genocide colony with a medieval level of development; that this level is set by an artificially created creationist religion implanted in the brains of colonists washed during cryosin, and is forcibly supported by the dominant all-powerful Church, which suppresses attempts at a scientific approach; that going beyond strictly prescribed technologies can be penalized by an in-orbit threshold system of kinetic meteorite bombardment already tested in the destruction of a minority that disagrees with the oblivion of all past history; that it has at its disposal few modern production facilities and weapons, Local Vehicles and Communications with Controlled Autonomous Orbital and Atmospheric Surveillance Facilities, decent electronic library and dumb, Advanced Computer Intelligence ; and, most importantly, that it represents the last hope for the rebirth of humanity. She takes on this incredibly difficult task, pre-adopting the male form of the sage Merlin on a patriarchal planet, Start gradually , like a useful virus, infecting first one cell of the body, and for this purpose chooses moving in the direction of the industrial revolution peripheral island kingdom Charis with active trade. by offering his services to the ruling dynasty and winning her trust by saving the life of the crown prince. She manages to put into circulation deliberately forgotten Arabic figures , positional system of number recording and abacus-counting, to revolutionize the textile industry, Shipbuilding and metallurgy of the kingdom with huge benefits for trade with other countries, Enhance your firearms , achieve the beginning of the construction of military galleons with powerful artillery to replace the existing galleys and training part of the fleet and marines new tactics before the troubled corrupt elite of the Church decides to destroy the too rich and suspiciously innovative kingdom by the hands of the five other maritime powers heeding it. In three decisive battles at sea, the kingdom's renewed fleet sweeps away the aggressor fleets, but this is only the beginning, because the Church is not going to lose its power and its influence - there are bloody religious wars ahead and a struggle for the minds of the inhabitants of the planet Safehold.