Aetius has been to Orion before, and in fact, she has been to all the rooms in the cave aside from Hydra. Yes, the owl has heard that Hydra was a dangerous room to go to, and was not willing to take any chances. What brought her back to Orion, was more research on the caves. Her hindsight spell, came into great use with these situations. As she flew above, she noticed a tall, huge tower encrusted with quartz crystals. She flew down to it, following the path of the stairs, landing into a hollow room at the very top. This was the first time she noticed the tower, but for now her focus was on this room. She successfully attempted to use hindsight on the room. She paid close attention to the vision. Oh, how the owl wished finding information was easier. In fact, it would be even more easier if the ancient masters of the caves could just give up the entire history and secrets of the cave, rather than hiding it from the gembounds here.

The vision Aetius sees is blurred, the sound a roaring mumble as if her magic did not completely succeed, but there was enough for her to see this:

Orion was bustling with many creatures, the city in the distance a beautiful structure with many blurred shapes moving between its buildings and alleys; of the tower, several creatures that appeared to be guards standing at its base, all around it—heavily armored creatures glittering with different shapes and sizes of quarts and diamond, weapons either in their hands or at their sides. The hollow room at the top was shadowed and hidden, unable to be seen.

@Aetius