I'm looking for a time travel book that my parents and I have both read. My father thinks he got it in the 50's.
Plot: A man is murdered while conducting an experiment and wakes up in a different body. It turns out that he time traveled into the future and took someone else's body. Every time he dies, it happens again. At one point, there is a group of people who tries to stop people like him, because he, and others, apparently, are killing people through time. He escapes from them. It turns out that time is cyclical or something and he loops back around to when he started, in a different body, and kills the person who killed him, before the murder happens. Then he (she, now, lol) is going to be executed and is wondering if he's going to time travel again when he is executed.