Blood Empire Avenged - Luke Irontree & The Last Vampire War, #5

Surrounded by a sea of enemies, Luke is left with nothing but desperate choices. Luke and his werewolf friends have escaped from Belgium. But now they're stranded in Luxembourg, surrounded by an army of werewolves and vampires. Their only hope is the Luxembourg alpha. Luke isn't sure who he can trust. But an offer of two private jets might be too good to pass up. Once his friends board the planes, the Luxembourg alpha betrays him, shooting him with a tranquilizer gun. After being sold to his enemies, Luke wakes up in a windowless stone cell.
Alone. With nothing but his own thoughts to keep him company, he is left to fight his impending descent into madness. When a scratching at the wall interrupts his isolation, Luke wonders if it's one more symptom of his failing mental health, or some new torture devised by his captors.