The Scream & The Silence
In 2665 a massive wave of metadimensional energy washed over human space. Spike drive craft in metaspace were annihilated instantly, and in the blink of an eye, every psychic in human space immediately suffered the consequences of catastrophic psychic burnout. The majority died instantly, with the handful that remained raving in the grip of incurable madness.
Later reconstruction placed the origin of this “Scream” somewhere in the Veil Nebula, but no records exist of any successful investigation. Too much collapsed too quickly for any sort of exploratory expedition to be sent. Humanity was suddenly stripped of every psychic resource. Without living mentors, new generations of psychics could not be trained without recreating the entire laborious research corpus of the now-erased Psychic Authority. It would take generations to mold functional mentors out of the untrained mass of native psychics.
There was no time to recreate the necessary training. The Jump Gates were dead, and the core worlds of human space collapsed with them. Countless colonies that relied on the bulk produce of agricultural worlds were left starving within months, their shipyards overrun by the desperate and ruined in the convulsive fighting over the few remaining spike drive ships. There was no possible way to feed a world of millions with the limited freight capacity of spike drive ships; only the Jump Gates and their massive slowboat freighters could move such masses of cargo, and the slowboats were too big to be retrofitted with spike drives- even if they could cross the stars quickly enough to make a difference.
Echoes of the disaster rippled outward. The frontier regions were still too poor and primitive to afford Jump Gates, so the worlds that remained on the edge of human space were forced to supply their own population with food and other necessities. Some of these worlds relied on small shipments of vital supplies from the core worlds. These luckless planets died when their motherworlds perished. Others were more self-reliant, but few of these had the necessary resources to build spike drive ships of their own.
Those few worlds that were able to construct the ships struggled as their psitech became useless and their shipments of vital core world components stopped.
Human space had collapsed into a welter of isolated worlds. Interstellar travel fell to the handful of spike drive ships that could be kept running on scavenged components and half-derelict spaceyards. The Silence had begun.