In 1967 Marcus ran away from home and traveled across the U.S. and through Central and South America, eventually living in the Caribbean. Recruited by a private military contractor, Marcus spent twenty-two years rescuing kidnap victims from Colombia and the Caribbean Basin. A firearms instructor, self-defense, and edged weapons instructor, cowboy, sailor, and scuba diving instructor, he brings real-world skills to his writing.

Currently, the author of eight novels and numerous short stories, he is sixty-five years old and travels across the U.S. in an RV.