The fantasy element of Touch is that some people --- some consciousnesses --- can transfer from person to person via physical contact. This makes those consciousnesses effectively immortal, given the prevalence of hospital-bed goodbye kisses, emergency first responders, and their own clever contrivances not to be stranded alone at death. (The action scenes thus enabled have a number of unusual elements layered over the usual dramatic side-switching reveal, as one might imagine.) There are many such consciousnesses, and they sometimes meet, and they of course become intimately entangled in the lives of people they inhabit.
Like The First Fifteen Lives of Harry August, this book seamlessly blended hook into explanation-of-the-gimmick into plot-development. The writing is solid, it caught my attention, and the plot and characters and meta-characters were fascinating. I wanted to know what happened! --- and not in the artificial Da Vinci Code sort of way. There are no cheap tricks here.
[Side note: Surprisingly little discussion or consideration of gender identity, class politics, etc., for a book in which these things are fluid and also by choice. Lots of discussion of degenerative joint pain in knees and hands. Arthritis is a much bigger deal than womanhood.]
This post's theme word is theurgy, "a system of magic to procure communication with beneficent spirits". Were you talking with that theurgic salesman?