George Warren’s 1979 Dominant Species is a stand-alone planetary romance novel.
Having had enough of war, mighty-thewed Oak and his addled companion Karth join a fishing fleet. The sea creatures of backward world Nuvelkebek are mighty indeed. Oak survives an encounter with one, thanks in large part to Karth’s intervention.
Mortally wounded, amnesiac Karth suddenly remembers suppressed memories. He charges Oak with a mighty task: find the Order! The grieving Oak has no choice but to accept. Alas, Karth was rather short on details, leaving Oak to discover horrifying truths on his own.