Afterlife Code — J.M. Erickson

There is an afterlife code . . .
Dr. Melanie Sage is a brilliant scientist who has developed a computer code for her brain implant to reduce the deleterious effects of her autism while improving cognition. With the help of her close friend and associate, Paula Dirac, she does the impossible: she creates an app on her smartphone to do just that.
Always logical and thorough, Sage triggers the application in the presence of her therapist, Robert Cobb, to ensure her safety. Unfortunately, she is unaware that his brain implant for managing posttrauma is much older, with little shielding. When Cobb begins having what looks like a seizure, she touches him to help but completes a circuit that launches them into coexisting lives, or what passes as lives.
As they pass through alternative existences, worlds where science and faith explore the edge of realities and unknown, inexplicable alternatives, they come across a man who knows them and provides them a warning to ensure they are “upgraded” when they die: “Make sure you have interesting lives and live to your fullest.”