The paperback version is somewhat different, and was published the same year by Ace Books, as illustrated by Leo and Diane Dillon.
The pharmaceuticals division of a large corporation has devised a potion that bestows immortality on a single application, without any need for follow up treatments.
In this kind of world, many men put off taking the immortality treatment for as long as possible.
He is a high ranking employee for a transnational corporation that one day approaches him with a confidential question relating to the discovery of an immortality potion that does the same thing that the current one does, but without the undesirable side-effect of turning off the sex drive in males.
They will do anything, including bribery, extortion, and murder, to get the information out of the pharmaceuticals lab before the process is made public.