Realising that the changed individuals represented invading minds, the race's leaders had them destroyed -- even at the cost of leaving the displaced minds exiled in alien space. They had had experience with even stranger transitions. When, through a mental exploration of space and time, they formed a rough idea of what the cube was, they carefully hid the thing from light and sight, and guarded it as a menace. They did not wish to destroy a thing so rich in later experimental possibilities. Now and then some rash, unscrupulous adventurer would furtively gain access to it and sample its perilous powers despite the consequences -- but all such cases were discovered, and safely and drastically dealt with.