Skylark Duquesne: Skylark Series, Book 4

Dick Seaton & Marc DuQuesne are the deadliest enemies in the Universe—their feud has blazed among the stars & changed the history of a thousand planets. But now a threat from outside the Galaxy drives them into a dangerous alliance as hordes of strange races drive to a collision with mankind!

Seaton & DuQuesne fight & slave side by side to fend off the invasion—as Seaton keeps constant, perilous watch for DuQuesne’s inevitable double-cross!