Time Waves: A Where is Now Story
by Mary S. Sheppard
This is the second book in the series.
Jeff, a former sheriff in 1895, returned with Amy to 2066, and was adapting surprisingly well to their happy life together. Things were also going well at BioTime, the pharmaceutical company where they both worked.
Their bliss would be momentary. The same technology that saved lives is trying to ruin theirs.