IC: The Cartographer
As he emerged from the dark, claustrophobic portal into the massive hollow center of the tower, The Cartographer gasped. He was utterly overwhelmed; he, nor any others from the Department had ever come across anything even remotely like this. The architecture, smooth and flowing, with a seeming endless loop of surface from the floors to the walls, evoked a wholly alien feeling, as though this forgotten corner of Ko-Metru was not merely that, but a planet all it's own. He reached into his pack, withdrawing a lightstone headlamp. It flickered to life, and he secured the fine Ga-Metruvian fabric straps taut around his masked head.
The lightstone, although the most powerful he could find at that size, was seemingly overwhelmed by the sheer size of the room. Tendrils of light grasped into the void, but could reach nothing beyond the center of the chamber, and the tree of ice that dominated it. Although apparently empty aside from the Cartographer, the chamber echoed amplified sounds from all around, turning the pitter-patter of water droplets into war drums, the scraping of feet into screeching violins. And then there were the carvings. Not a single inch of wall space was spared, and in fact, even the inner roof dome seemed to be completely covered in these strange runes; sharp, angular, almost violent in nature - and definitely unlike any known script in the recorded Matoran Universe. Even to a veteran explorer such as the Cartographer, any quick attempt to translate would be a literal and figurative stab in the dark.
With his curiosity temporarily sated, and his goal back in the forefront of his cortex, the Cartographer turned his attention to the middle of the chamber, the ice-tree, and the small, light-emitting hole in the center of the roof. He removed his pack again, and began withdrawing his kit: one length of Ga-Metruvian hand-woven climber's cord, one anchor, and a pair of ornately-carved climber's picks that he'd had made by his old friend, Nuparu, what seemed like years ago. With his pack resecured, his cord and anchor strapped to his chest, and picks in hand, he approached the tree. The Cartographer's hand ran along it's surface; and although this tree appeared, and definitely was carved, it had no evidence of tool marks. Something that deserved a second look, but not today.
His pick dug easily into the ice-bark of the carved tree, as did the other with a satisfying crunching-slicing sound. Pulling himself upward, his foot spikes found a home in the tree, and so carried on the cyclical climb. Aside from a few weak spots on thinner limbs as he ascended the tree, he found little other trouble. The Cartographer reached the highest limb, mere feet from the roof, and the strange hole. He pulled himself into the limb, and began to peer up into the hole as he stood up.
OOC: @Unreliable Narrator I await you to make the next move.