Plot

Emm Luther is a planet ruled by a single, worldwide theocracy

Theocracy

Theocracy is a form of organization in which the official policy is to be governed by immediate divine guidance or by officials who are regarded as divinely guided, or simply pursuant to the doctrine of a particular religious sect or religion....

. It is sparsely populated, and a couple of railroads run up and down the coasts of the largest continent. Earth sends secret agent Sam Tallon to Emm Luther to infiltrate the theocracy, and extract the coordinates of the jump points, a closely guarded secret.

When the religious secret police

Secret police

Secret police are a police agency which operates in secrecy and beyond the law to protect the political power of an individual dictator or an authoritarian political regime....

 discover he has false credentials, and has entered the world under false pretenses, a frantic chase and flight ensues, terminated only when they break down his hotel room, and a high-ranking Security Agent fires his dart gun

Dart gun

dart gun may refer to:*A Tranquilliser gun, that fires a tranquilizer dart for animals*A toy gun that fires a dart...

 into Sam's eyes, permanently blinding him. He is taken to a secret prison complex in the southernmost tip of the most distant continent to convalesce. While he is there, he enlists the aid of the scientific elite in the ranks and files of the political prisoner

Political prisoner

According to the Longman Dictionary of Contemporary English, a political prisoner is ‘someone who is in prison because they have opposed or criticized the government of their own country’....

s there, and together they design a pair of electronic "sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

" eyes. Equipped with an audio feedback system depending on which direction he turns his "eyeglasses" or headgear, he discerns a different kind of audio tone.

Then, with the aid of two other prisoners, they might have a chance at escaping the prison, traveling across the diameter of the planet, and reaching his secret contact. Managing to get the necessary equipment, they escape, wading through 20 miles of swamp and shallows. Tallon manages to cross the single continent of Emm Luther, rendezvous with secret agents whose covers are not yet blown, and escape the planet by boarding a spaceship and departing from the local planet. Later, he finds he must master the intricacies of the "jump stick," a form of jump drive

Jump drive

A jump drive is one of the speculative inventions in science fiction, a method of traveling faster than light .Related concepts are hyperdrive, warp drive and interstellar teleporter. The key characteristic of a jump drive is that it allows a starship to be instantaneously teleported between two...

 via portals to "null-space" (a hyperspace

Hyperspace (science fiction)

Hyperspace is a plot device sometimes used in science fiction. It is typically described as an alternative region of space co-existing with our own universe which may be entered using an energy field or other device...

parallel universe passing through which instantaneous space travel is achieved).