Concealed radio receiver

The Concealed radio receiver gives Piet Hoffmann a hidden listening channel inside Aspsås Prison, where movement and communication are tightly controlled. Small enough to be concealed in a modified book and then worn in his ear, it links the prison workshop to a transmitter near the church tower. Its importance lies not only in what it carries, but in the reversal it creates: while confined and apparently cut off, Hoffmann can hear people outside his immediate space—and discovers that they can see him too.

Construction and concealment

The receiver appears as part of Hoffmann’s improvised equipment made from altered books. In one book he finds a cavity containing a detonator and a receiver described as penny-sized. The same book also conceals two long lengths of pentyl fuse and a small quantity of nitroglycerine. These components establish a practical setting for the receiver: it is not a conspicuous standalone instrument, but one element hidden among materials that Hoffmann has extracted from ordinary objects.

The device’s concealment is significant in a prison environment organized around controlled access. Hoffmann has been brought into Aspsås Prison under escort, searched, and assigned to a cell; later, after ten days, he has spent most of each day alone behind a locked door. The receiver’s small scale contrasts with the institution’s heavy gates, restraints, and doors. The evidence does not explain precisely how it passes each security check, but its movement from a book into Hoffmann’s clothing shows how the concealed object becomes usable beyond the place where it was assembled.

From hidden object to listening channel

In the workshop, Hoffmann has prepared his surroundings carefully. He has noted the surveillance cameras, the workbenches and pillars, and the positions of tools and equipment. With two prisoners held nearby, he takes clothes to a workbench beside the large windows facing the church, puts the receiver in a front pocket, and then places it in his ear. Looking toward the church tower, he listens to the faint sound of wind reaching the device and recognizes that the connection works.

That first test changes the receiver from stored equipment into an active channel. The faint wind is not the information Hoffmann ultimately needs; it confirms that the signal is coming through. Soon other sounds replace it. Hoffmann hears activity on the other end, runs to the window, and sees four people standing on the church tower and looking toward him. A brief shadow appears at the edge of the window and disappears. The receiver has therefore disclosed more than outside conversation: its use coincides with Hoffmann realizing that the people monitoring or communicating through the system have a view of his position.

What the receiver lets Hoffmann hear

The receiver provides unusually clear sound. Hoffmann adjusts the thin metal disc with his index finger, pressing the earpiece more firmly into his ear; the voices then come through as if the speakers were addressing the transmitter directly. Among the conversation, someone asks who a person is, and another identifies him as Ewert Grens, a detective superintendent at the city police. The exchange supplies Hoffmann with a name and an institutional connection at the moment that the people on the tower have become visible to him.

The listening channel also carries sounds that are not spoken information. Hoffmann hears a gun meet a wooden floor, followed by the sound of a heavy body falling. Shortly afterward, a speaker states a distance of 1,503 meters, and another asks for confirmation. The sequence places the receiver within a tense, unfolding operation involving people on the tower and activity inside the prison. The text does not make every speaker or action fully explicit in these moments; the receiver instead gives Hoffmann—and the reader—fragments whose significance emerges through their order and proximity.

Narrative and thematic significance

The receiver makes separation inside the prison incomplete. Hoffmann has been isolated by institutional routine, first in a cell and later in voluntary isolation, where contact with prisoners from other units is restricted. Yet the listening device allows sound to cross the boundary between the workshop and the church tower. Its small size enables that breach, while its dependence on a signal means that Hoffmann remains exposed to what the channel carries and cannot control every part of the exchange.

The object also reverses the direction of surveillance. Hoffmann has mapped the prison and studied its routines, preparing to act within a system designed to watch and confine him. Through the receiver, he gains access to voices beyond his immediate reach; at the same time, the sight of four people on the tower makes clear that he is visible from outside. The device is thus neither a simple instrument of mastery nor merely a concealed aid. It opens a channel while revealing the limits of concealment: information reaches Hoffmann, but so does evidence that others have located him.