The book of Malachi
(Book)

"Malachi is a mute thirty-year-old man, performing mind-numbing factory work, when he gets an extraordinary job offer. In exchange for six months as a warden on a top-secret organ-farming project, Frasier Pharmaceuticals will gift Malachi the power of speech and graft him a new tongue, after his was cut out when he was a boy... Far out to sea on an oilrig, Malachi finds himself among warlords and mass murderers. But are the prisoner-donors as evil as Frasier says? Do they deserve their fate?"--Fantasticfiction.com.