While trying to take down a drug cartel that deals with memory altering drugs, things go awry, and Batman wakes up with no recollection of the last five years.
As a result, his family must now race against time to find the antidote, while also having to deal with a Bruce who still thinks Jason is Robin. A Bruce who doesn't recognise most of them. A Bruce far less jaded and cynical than the one they're used to. A Bruce who still cares.