At some point prior to 2268, the Tholian Assembly began experiments to create a prototype land based non-lethal defensive system that was based on the principles of the web generator. The purpose of these devices was to capture the inhabitants of planetary based installations without harming them or the structures that they were occupying. This would have allowed the Tholians to easily transport their captives from the captured areas and detain them whilst the Assembly moved in to occupy the newly acquired territory. Initial trial tests were conducted on the Klingon agricultural colony located on Traelus II but the results proved to be disastrous as the devices led to the death of those engulfed by the web generator. The Klingon Empire was furious over the matter and threatened vengeance over the Tholian Assembly. Investigators from the Tholians later concluded that their scientists did not take into account the radical physiological differences between lifeforms in the galaxy. The incident was covered up by the magistrates of the Tholian Assembly who attempted to ensure that no knowledge of the event was recorded or discovered by the other interstellar governments.
The prototype emitter was left at the designated site until the Tholians could retrieve. However, unknown to them, the Starfleet vessel USS Defiant uncovered the colony and took one of the emitter arrays for study. Their journey back to base, however, led them to be trapped within an interphasic rift in a region of space that was claimed by the territorial annex of the Tholian Assembly who were unaware of the discovery of their web generator emitter.
In 2367, the USS Defiant emerged from the interphasic rift once more and in an effort to improve diplomatic relations with the United Federation of Planets, the Tholian Assembly invited a Starfleet ship to aid in recovery of the ship. The crew of the USS da Vinci were tasked with this mission where they uncovered the Tholian prototype device. After learning of this, ship commander Nostrene informed the High Magistrates who ordered him to destroy all evidence of the find - including the Starfleet vessel even though it would risk a conflict with the Federation. (SCE eBooks: Interphase, Part One, Interphase, Part Two)