Deep under Gotham City lies a subterranean echo of a lost time. This abandonedworld has lain uninhabited for decades…until tonight. Now, Damian Wayne is thesole human resident of these abandoned catacombs…imprisoned by the entityknown only as Memento. A father is desperate to track down his son, but willBatman be able to descend into the bowels of the city in time to save Robin? Or willthe Dark Knight’s mind spiral into madness first?