These films only loosely adapted their source material, choosing to adopt a comedic tone, rather than the serious tone of Hamilton's books. At the end of the fourth film, 1969's The Wrecking Crew, it is announced that Matt Helm's next cinematic adventure would be The Ravagers (presumably based upon this novel).
These films took liberties with their source material, opting for a comedic approach instead of the serious tone found in Hamilton's books.  The fourth film, 1969's The Wrecking Crew, announced that Matt Helm's next cinematic adventure would be The Ravagers (presumably based on this novel).