Brine And Bruise. Undertow, #35

He took her brother's life in the ring. Now, she holds his in her hands. Cosima Reyes is a woman driven by a single, clinical obsession: find the man who killed her brother Nico. Nico was an underground fighter who died in a rigged bout controlled by the ruthless "Undertow Sins" circuit. To hunt down the culprit, Cosima infiltrates the corrupt offshore fighting syndicate, hiding her identity behind a medic's badge and a cold, professional armor.
Enter Lorcan Priest. Undefeated, heavily scarred, and dangerous, he is the circuit's prized weapon. He is a man who uses his knuckles as armor against a past that has already drowned him once. Cosima marks him as her prime suspect, tracking his every fight, his every scar, waiting for the perfect moment to execute her vengeance. But the ocean doesn't care about human scores. When a violent tropical storm rips through the Gulf of Mexico, the fighting barge splits down the middle, throwing them into a liquid abyss.
Left with nothing but a sinking makeshift raft and a rapidly depleting water supply, Cosima and a severely injured, infected Lorcan are forced into the most brutal match of their lives: survival. In the agonizing, sun-bleached expanse of the open sea, the boundaries between hunter and prey erode. Using a boat knife and fishing line, Cosima fights to save Lorcan's rotting hand and fracturing mind. But as the fever burns away his defenses, the absolute truth finally surfaces.
Lorcan was indeed Nico's final opponent-but he didn't know the fight was fixed, and he has spent two agonizing years carrying the shattering weight of a boy dying in his arms. Now, the secrets are bare. The lies are washed away by brine and blood. If they manage to hit solid ground, they will no longer be fighting each other. Armed with her clinical evidence and his lethal instincts, they will turn their fury toward the powerful syndicate that orchestrated their ruin.
But out here, where the horizon never ends, they must first figure out if the bond they forged in the dark can survive the harsh light of the shore.