Contain by Saul Tanpepper

THEY SAID THE BUNKER WOULD KEEP US SAFE. THEY LIED.
3 years have passed since Finn Bolles fled to the safety of B-8, one of ten apocalypse bunkers specially built to survive an extinction-level plague known as the Flense. 3 years of total isolation and hiding from the terrifying creatures known as Wraiths.
Then, an uninfected stranger appears at their front door spouting unbelievable claims of a cure. Should they risk leaving their safe haven to help the madman find it? Their destination: B-12, a bunker that’s not supposed to exist. With Humanity’s fate on the line, how can they refuse?
But someone in their group is desperate to keep the secrets of the Flense buried, and they’ll do whatever it takes to make sure they are never exposed.
Even if it means unleashing the deadly, terrifying Flense against them all.