The anomaly's primary purpose was to prevent the Thessian brane from being destroyed. This included—and particularly emphasized—stabilizing Thessia Major, although its sister planet and all of the moons in the system were also accounted for. The crust and core of Thet's natural satellites is uniformly very high in iron and other ferromagnetic minerals, naturally indicating that an electromagnetic field would be most appropriate to augment the already wildly complex plane-stabilization magic.
This, Tetragnostica hoped, could be strong enough to hold the entire planet together, but not endanger the brane itself. In the end she designed an extremely complex mechanism to carry out the task, intending that the entire crust would be held in place, with a magnetic field that changed direction periodically to keep the terrain in one piece. A complicated fractal governs the distribution of this behaviour over space, originally to relieve tidal stress, and the whole field was designed successfully to be safe to biological tissue and contemporary Thessian technology, as Tetragnostica anticipated these would still be necessary to evacuate following the Shattering event.
If the anomaly had not been employed, the entire brane's contents would have been snuffed out, as it unravelled and shattered into countless dimensionless Planck-scale spaces; if it had gone off perfectly, there would have been severe earthquakes, a few complaints, and life would continue as usual. For some reason, things did not go as planned; the anomaly did not hold everything quite together, causing severe fragmentation of Thet's land, and vertical jitter, as newly-formed floating islands tried to find their ways into the preferable orbits generated by the equation governing the distribution of magnetic forces. The islands maintained their previous orbital trajectories, continuing to spin and only occasionally crashing into each other.
Despite its chaotic, bluish appearance and relative approachability (habitable islands may be as close as 100 km away from the surface), the anomaly was formerly a Population I star, Astra Thessiae. No other power source was sufficient for the task at hand.
It is not known what went wrong with Tetragnostica's spell. All attempts to analyse the magic of the anomaly have failed due to its staggering complexity, leaving many to posit interference from their favourite divine force.
The actual moment of destabilization lasted less than a millisecond, but resulted in immense energy discharges that rapidly disintegrated significant portions of Thet's various natural satellites, breaking up the crust and upper levels of the mantle of Thessia Major into small fragments, few larger than 20 km in diameter. Most large settlements were only exposed to hard vacuum for a matter of seconds, as they were guarded by Planar Sentry posts long-since equipped to deal with minor incursions. A number of settlements, including the metropolis of Survaní Doisseia, were destroyed completely, being directly along the path of the primary discharge that tore through the planet.
The Hatel are largely credited with saving the population of Thet with their immense IAC (interstellar arcology craft) vehicles, five of which were stationed at Thessia Major at the time. Several Lyrisian ships, such as the Solar Prominence, were also adequately equipped to facilitate evacuation through matter beaming, and the efforts were coordinated automatically between ship computers of both fleets. Prioritization was given to protecting those not secured within settlements, although the available time to stage recoveries was so terse (70-80 seconds) and the conditions so severe (some portions moving at > 40 G, significant eruptions from the planet's core) that the estimated recovery rate was only 5-6%. After 144 seconds, rescue efforts were switched to focusing on secured settlements in descending order of danger. In total, just shy of 47,000,000 inhabitants were rescued in this way. Small parts of Kunanoten and large portions of Nea Trestua, such as the Collegium arcology, were never evacuated, having adequate protection.