The Blood Spire is an artifact of unknown origin located on the planet Golgotha. It is a tower measuring 250 meters in height, with the base suspended a short distance above the surface of Golgotha through unknown means. The Spire tapers toward its summit, swelling into a bulb-shaped "minaret" before tapering again into a sharp point. The exterior of the structure is covered with geometric patterns overlain with what appear to be branching vein-like tubes.
While virtually nothing is known about the Spire's purpose or history, it appears to be designed as a sort of test for intelligent life-forms that come across it. The interior is composed of a linear sequence of rooms linked by doors, spiraling upwards toward the summit, with each room containing a puzzle that must be solved before access to the next room is granted. The puzzles invariably focus on some area of mathematics, such as prime number theory or topology, and become steadily more difficult as one progresses through the rooms. The dimensions of the doors also change subtly with each room, becoming smaller and narrower.
If one chooses an incorrect answer to a puzzle (or takes too long to answer, in the case of later rooms), a "punishment" is delivered by the tower. These punishments vary wildly, but always involve some form of dismemberment or other grievous bodily injury.
One possible objective of the Spire, as theorized by Richard Swift, is to force its test subjects to alter themselves in order to overcome its challenges. The ever-increasing complexity of the puzzles, combined with the deadly "punishments" and steadily decreasing size of the doors, are an incentive for suitably motivated investigators to augment themselves through cybernetic means, becoming intellectually faster as well as physically more compact and resilient. It is conjectured that the Spire might have some use for individuals that have undergone such drastic augmentation, and that they will be "harvested" if they manage to reach the top of the tower.