Timeline - Michael Crichton A man is found wandering in the desert southwest near Black Rock New Mexico. He is taken to a local hospital where he dies. An autopsy, required by law, reveals some strange anomalies. His fingers, which had appeared gangrenous, had veins that did not match up, and his heart had similar conditions on the walls. The man should not have been able to live more than a few hours, let alone the seventy plus years he turned out to be. His fingerprints revealed his identity to be that of a physicist working at a very high-tech and secret facility some two hundred miles from where he had been found. He appeared to be delusional, muttering all sorts of bizarre poems and he had no identification other than a strange ceramic disk that turned out to be an ID device from the corporation. He also had a piece of paper with strange dots and letters that appeared to be Monastaire Marie, a monastery that had burned to the ground in the fourteenth century.
The corporation had been a substantial supporter of an archaeological dig in France that was restoring the monastery in the drawing. There the researchers discover a pair of spectacles that are clearly twentieth century and a note asking for help that could only have been written in the fourteenth century. They worry the site has somehow been contaminated and they report their findings to headquarters. The historians and archaeologists are summoned to New Mexico to the headquarters of the corporation where they are stunned to learn that this corporation, for monetary reasons of its own, had perfected time travel based on theories of multiverse and quantum physics. Crichton always does his homework and the explanations of fourteenth century France and quantum physics are clear and appear accurate (not that I would have a clue about quantum physics.) They are sent back to retrieve a research who has not been able to return. Regretfully, as they well knew, the area was also at that time in the midst of the Hundred Years War. One of the guards sent along to help them insists on taking along weapons covertly, despite admonitions not to, and a grenade explodes in the transmission room on his return. The travelers have only a thirty-nine hour window to return so they must battle language problems, warring factions, and other travails to retrieve the professor who had been left behind.
It’s a great story to read or listen to if you suspend some rational thought. The twentieth century visitors are just a little too competent in making there way around.