Under Pressure is a short novel that is wound so tight there is an unmistakable release when the novel draws to a close. The novel has gone by several titles over the years. When it was first serialized in Astounding Magazine (1955-56) it was titled Under Pressure later it was republished in book format under its original title as well as The Dragon In The Sea and 21st Century Sub. The book has long been a favourite of submariners which is hardly surprising given the clarity with which Frank Herbert relays the incredible pressure submariners are under when they are on a mission.
Under Pressure begins in medias res with a string of losses of 20 submarines and their slugs by the west who are trying to get into eastern territory, steal oil, and return to the west with the much needed liquid. There has been a higher than normal incidence of mental problems afflicting submariners which has lead to BuPsych (the bureau of psychology) being asked to put a man on board with the crew to evaluate the captain of the Fenian Ram in place of the electronics officer who has had a breakdown. These small four man subs are pressure cookers to begin with but when you add into the mix the potential of an enemy mole, sabotage, running deep into enemy territory the feeling of claustrophobia is unremitting.
Frank Herbert loves to link religion and psychology and does so with great efficacy in Under Pressure. This novel could be a study in schizoid behaviour as much as it is a work of science fiction. This book is a good and quick read.
NB: There is an interesting development after the publication of Under Pressure (1955) of the Dunlop Dracone, invented at Cambridge in 1958 by Sir William Hawthorne a device which is still in use that looks and operates exactly as the slug in Under Pressure does.