Inferno begins with the readers being reintroduced to the same protagonist who was part of the author's previous two novels entitled The Da Vinci Code and The Lost Symbol. This protagonist, Robert Langdon, is all set to be a part of this new and intriguing thriller as well.
From what Robert is able to recollect, he was walking through Harvard's campus, when he suddenly finds himself in a hospital in the city of Florence, recovering from a head injury. Robert also finds himself with a mysterious cylinder that bears Dante's famous poem titled ‘The Divine Comedy'. However, things take a turn for the worse, when a female assassin tries to murder Robert.
Inferno then has Robert and a doctor named Sienna Brooks start off on a journey to find this assassin. As they search for the assassin, they encounter many dangers that could cost them their lives. However, much to their surprise, these dangers have solvable codes that focus on Dante's Inferno.
When Robert has no other choice but to unravel the mystery that concerns the Inferno, he faces a severe threat to his life. Nevertheless, he must risk all those threats to save the world from impending doom.