Item from dark-forest by
Bill Hines's neural imprinter, marketed as a confidence-builder for the Space Force — secretly substituted by Keiko Yamasuki to imprint defeatism at the bedrock level.
The Mental Seal does not persuade. It writes. Whatever proposition is loaded into it becomes, for the recipient, a fact below the level of doubt — a thing they cannot argue themselves out of any more than they can argue themselves out of gravity. Hines designed it to produce confidence in human victory; Keiko's substitution made it produce certainty that humanity must lose. The 'Imprinted' make up an unknown but significant fraction of post-program Space Force personnel, and they cannot be detected from the outside.
A skullcap apparatus with electrode arrays and quiet humming projectors, worn for several minutes under medical supervision. Patients describe a sensation like a hot thread being slowly drawn through the back of the head. No visible aftereffect.
Also known as: the Imprinter, the Confidence Apparatus