The author meditates on the cold war as a future event that escalates to the point of global catastrophe—superpowers threaten mutually assured destruction, the end of the world. To escape the inevitable extinction of the human race the Americans invest in the Man Plus project as a means to migrate and survive on Mars as their last hope.
Roger Torraway is the runner-up candidate to allow scientists to biologically engineer him into a cyborg capable of enduring the Martian atmosphere. How terrified would you be, though, if you learnt that the same technicians botched the job the first time around, frying the poor subject's mind and damaging his heart because the body was not correctly configured for foreign stimuli?
From the very beginning the text is inherently more concerned with the feelings of the individual rather than the technobabble. Compared to the genre as a whole, this intimate approach to storytelling sets the prose apart from its contemporaries. After all, Man Plus did win a Nebula award.
While the premise of redesigning a person for colonisation and survival is plausible we are not meant to be too concerned with the technical particulars. Let your imagination enjoy the journey. This is not to say that the science fiction is weak; this is a testament to the real story that uses the setting and the innovations as a vehicle to drive an important message. Roger progressively transforms from human to alien and struggles to reconcile with his new self. Also, the trial and error method of experimentation lends itself well to the theme of failure, which is a fascinating trope of being human.
Rather than gloss over sex, Pohl embraces the importance of our most base and carnal needs—something a lot of writers conveniently avoid. We learn that Roger's penis is removed much to the wife's disapproval. Although the writing is not intentionally misogynistic, quite the contrary, it is a product of its time and should be lauded for engaging in sexual discourse as well as attempting to subvert gender roles—the text introduces a female scientist for example.
Emotion, feeling and the absence of pleasure as we know it is central to the focus of Man Plus because the protagonist is losing his identity, his human nature and his free will. There is also a twist in the plot in the final chapter that will send your mind soaring post-revelation. For all we know this could be our future and Man Plus is the cautionary tale to prevent Armageddon. Read. Learn. Enjoy.