In the shade of Vesuvius the lives of different people are interwoven...

Plot:
Marcus Attilius Primus arrives in the Bay of Naples from Rome to take charge as aquarius (hydraulic engineer) of the Aqua Augusta, the aqueduct that supplies water to the many towns in a region encompassing the Bay of Naples and Mount Vesuvius. The nine important towns are, in sequential order, Pompeii, Nola, Acerrae, Atella, Naples, Puteoli, Cumae, Baiae, and Misenum. Attilius' predecessor as aquarius, Exomnius, has mysteriously vanished as the springs that flow through the aqueduct begin to fail, lowering the supply of water available to the region's reservoir, the Piscina Mirabilis in Misenum.

Then, dramatically, the flow of water stops entirely. Attilius concludes that the aqueduct must be blocked somewhere close to Mount Vesuvius, since reports claim a shut down of the system just before Nola, meaning that towns from there through Naples and Misenum are without any water supply. With aid from Pliny the Elder, whose fleet is docked at Misenum, Attilius assembles an expedition to travel to Pompeii, the only town not connected to the water grid, and then on to the blocked section of the Aqua Augusta.

While Attilius' expedition is there, the aquarius himself becomes embroiled as part of a plot of the former slave and land speculator Numerius Popidius Ampliatus. Ampliatus is planning on offering a cheap water supply to Pompeii, which Exomnius, the previous aquarius, had helped him do while stealing from the imperial treasury.

Attilius' questions and studies make Ampliatus suspicious of what Pliny the Elder and his nephew later discover—thousands of Roman sesterces at the bottom of the reservoir that should have gone to Rome and which 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 is performing repairs to a collapsed section of tunnel in the region around Mount Vesuvius.

The eruption of Mount Vesuvius on August 24 overwhelms Pompeii, Oplontis, and Herculaneum. Attilius risks his life and comes back to Pompeii to find Corelia. Attilius and Corelia dig their way through the aqueduct tunnel, which the springs are beginning to fill—which carries a high risk of drowning. 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.

At the end of the book Attilius and Corelia enter the aqueduct just as the waters are coming back to full flow. The last sentence of the novel reports a local legend that a man and woman had emerged from the aqueduct after the eruption—implying that Attilius and Corelia likely survived the trip up the aqueduct.

Comments:
A very well researched book, which gives a good insight into the last days of Pompeii. As a nowadays reader I feel bad, that I know, what will happen and cannot tell them to leave the town - or better the complete bay. Interestingly the story of Pliny is mixed into the fictional episode describing Attilius' attempt to repair the aqueduct as well as his love for Corelia, whom I thought to be lost and already dead, until Attilius is able to make his way back to Pompeii to find her...