The Corps 3: Brink (Book Three of The Marshal Command Series)
by Isaac Bader
Former Lead Marshal Brian Weber travels to Brazil in search of answers. He starts by locating the missing M.C.C. ship Britannia, somewhere deep in the Amazon. Only, what Weber finds leads him and his companions to more questions. Weber is forced to take on new allies, fight old enemies, deal with a hired assassin, and all while doing everything he can to survive and protect the few he cares about.