From the series: The Ghost Crew series.

THE OBSIDIAN VAULT

Book #5 of The Ghost Crew series.

About

They broke the global syndicate. Now, they’re going after the vault.

Former NYPD Detective Elias Thorne, his master-thief brother Leo, and their elite crew of specialists survived the fallout of the Paris Protocol. But four billion dollars of orphaned cartel money is still missing, and it’s sitting in the most impenetrable bank on the planet: The Obsidian Vault.
Controlled by Julian Vance, a rogue MI6 spymaster turned underworld banker, the vault is an off-the-grid, sovereign fortress built directly into an active, deep-sea geothermal caldera in the Celebes Sea. Bristling with anti-ship missiles and a private army of mercenaries, a surface approach is suicide. The only way in is to navigate a heavy-duty submersible through scalding thermal plumes and drop straight into the belly of a submerged volcano.
But the Ghost Crew isn’t the only one hunting the ultimate payday.
Disgraced Interpol Director Helene Rousseau has survived her downfall, and she has unleashed a tier-one black-ops kill squad to bring the Thorne brothers back in body bags. Forced into a fragile, terrifying alliance with Viktor Markov—the ruthless Bratva cleaner who once tried to kill them—the crew is plunging headfirst into a deadly trap.
Caught in a brutal three-way war between elite mercenaries and Vance’s private garrison, the crew must orchestrate a flawless digital siphon while the environment itself turns against them. With the geothermal grid failing and the magma core threatening a catastrophic eruption, Elias and Leo must pull off their most explosive heist yet before they are buried in liquid fire.

The Obsidian Vault is a scorching, high-adrenaline thriller that pushes the heist genre to the absolute breaking point. Perfect for fans of James Rollins and Mission: Impossible, this explosive adventure proves that the deepest secrets are the hardest to steal.