Pompeii is a novel by author and journalist Robert Harris published by Random House in 2003. It is a blend of fictional characters with the real-life eruption of Mount Vesuvius on August 24, 79 that overwhelmed Pompeii and its surrounding towns. Pompeii is especially notable for the author's references to various aspects of vulcanology and use of the Roman calendar.

On August 22, Marcus Attilius Primus arrives from Rome to take charge as aquarius (engineer) of the Aqua Augusta, the aqueduct that supplies water to Pompeii and eight other towns along the Bay of Neapolis. Attilius' predecessor as aquarius has mysteriously disappeared as the springs that flow through the aqueduct begin to fail, lowering the supply of water available to the region's reservoir. With the aid of admiral Pliny whose fleet is docked at Misenium , Attilius assembles an expedition to travel to the section of the Aqua Augusta near Mount Vesuvius.

While Attilius' expedition is there, the aquarius himself becomes embroiled in the plot of former slave and land speculator Numerius Popidius Ampliatus to become the provider of low-cost water to Pompeii, which the previous aquarius helped him do while stealing from the imperial treasury. Attilius' questions and studies make Ampliatus suspicious of what Pliny later discovers -- thousands of Roman sesterces at the bottom of the reservoir that should have gone to Rome and which the Attilius' predecessor had intended to retrieve once he'd emptied the reservoir. Ampliatus' daughter Corelia gets Attilius the proof he needs from her father's written records when he's at the foot of Mount Vesuvius. As the eruption on August 24 overwhelms Pompeii and neighboring towns, Attilius and Corelia dig their way through the aqueduct tunnel which the springs are beginning to fill. Ampliatus is killed when he refuses to evacuate the city, and Pliny dies when the sailing ships he tries to evacuate the citizens in are overwhelmed by the volcano.