In the words of the fine litigators at The Good Wife's Lockhart/Gardner, let's stipulate that John D. MacDonald's "Susceptibility" is a deeply problematic work. The planet of the pioneer vixens is a weirdly troublesome image, even before we get to the fact that the entire story is predicated on Deen's lack of agency. All things considered, "Susceptibility" hasn't been collected or reprinted since 1978, and that feels about right.
However, "Susceptibility" does tackle several of the themes relevant to this week's "action hero" focus. (And, to be fairn, the book's terrible sexual politics are pretty on-theme as well.) These include the action hero both as a 'lifestyle choice' and as a means of guilt-free rebellion.
Sean Mallow lives in a delightfully Utopian future with everything free and comfortable and filled with joy. Yet still he is driven to live on the fringe of that society. As a Praecursor, he is someone that goes into relative (but not absolute) danger. Sean's clearly flung himself into his Praecursor task, he's even got the manual memorised. But, as Deen demonstrates, even that isn't enough for him. Ultimately, he chooses more - more danger, more risk, more work and more adventure. "Susceptibility" is set up as not as a conclusion, but as an origin story. His final decision is the moment where Sean Mallow decides to step outside the rules of society and devote himself to a more adventurous path.