Krakatit

A barely conscious man is placed under intensive care by a doctor and a nurse. His hands show severe burns and cuts, and the doctor orders oxygen to stabilize him. This opening establishes Prokop's frail condition as the mystery begins.

The delirious man wanders along a city street, muttering and disoriented. An old classmate, Jiří Tomeš, greets him and they confirm the man's name is Prokop. He babbles about an explosion and something he calls krakatit.

Jiří escorts Prokop to his apartment and puts him to bed. Recovery is slow and Prokop's memory remains hazy, with the earlier clues about krakatit still unclear. The scene deepens the mystery of what happened to him.

In a dream, a university professor questions Prokop about krakatit and its significance. He explains that it is a powerful explosive and sketches a formula. When he awakens, Jiří has written down the formula.

Prokop wakes alone in Jiří's apartment to a note saying Jiří has gone to see his father. A veiled woman rings the bell, begging him to deliver a letter to Jiří. Still unsettled, Prokop decides to visit Jiří's father.

An old mail carrier offers Prokop a lift to the countryside to visit Jiří's father. On the way, he learns that Jiří has not visited his father in a long time. Upon arriving, Prokop collapses.

Prokop slowly recovers under the care of the countryside doctor and his daughter Anči, but his memory remains fragmented. He still cannot recall the events that led to his illness, leaving krakatit's origin unresolved.

A newspaper story about krakatit—promoted by a man named Carson from Balttin Works—reawakens Prokop's memory. He remembers the laboratory explosion and hurries to confront those involved. The trail ties Jiří to the broader krakatit conspiracy.

Carson explains Balttin's interest: they have Prokop's stock of krakatit and the formula but lack the production method. They offer him employment to aid their research, and Prokop declines, but they forcibly bring him to the Balttin palace to work in a chemical laboratory.

In the palace, Prokop begins a romance with Princess Wilhelmina Hagen. He also realizes his true attraction to the veiled woman from Jiří's apartment, complicating his loyalties and emotions within captivity.

The Balttin executive offers to arrange Prokop's marriage to the princess if he provides krakatit. In anger, Prokop detonates the laboratory and, with his coat loaded with explosives, confronts the princess, whose face dissolves in the blast. He escapes amidst chaos.

Prokop escapes with help from an ambassador named d'Hémon and visits a secret society of former world leaders and weapon dealers who worship war. They hail Prokop as Comrade Krakatit. As turmoil erupts, a can of krakatit spills and members scramble to seize the powder for themselves.

D'Hémon leads Prokop to the top of a hill of magnetite, where Prokop's old laboratory has become a secret radio station. Prokop is forced to push a button, triggering stockpiles of krakatit to explode across European capitals. D'Hémon explains that the explosions are meant to spark a controllable war.

Prokop finds himself in a desolate, concrete landscape and seeks Jiří Tomeš at a relocated laboratory. He is refused entry but is allowed to meet a lab assistant to whom he gives the veiled woman's letter. The factory back at the distance explodes, signaling widespread devastation.

An old mail carrier reappears and gives Prokop a lift back toward civilization. The driver suggests he should invent something that makes people's lives easier instead of killing them. Back at the hospital, the doctor notes that the patient is breathing normally and the oxygen mask can be removed.