Harvard symbologist Robert Langdon wakes in a Florentine hospital with no memory of how he got there, only to find himself pursued by unknown assailants. He teams up with a young doctor to unravel a trail of clues drawn from Dante's vision of Hell, which leads them across Europe in a race to prevent a billionaire's catastrophic plan to drastically reduce the world's population. The conspiracy proves more layered than it first appears, with loyalties shifting as the deadline approaches.