The House of Hades is the fourth installment in Rick Riordan's Heroes of Olympus series, where the saga continues with demigods embarking on a crucial quest. The story picks up with the characters trying to close the Doors of Death, crucial for preventing the resurrection of the Titan Kronos. The narrative alternates between two groups of heroes, one journeying through the underworld while the other travels through the mortal realm faced with its own...