Impatience

The machine should have rejuvenated every aspect of his old, tired body.

Marcus cursed himself. If only he had taken more time to make sure his maths was right and that the programming of the black box had been taken to the highest level of sophistication... or at least, if only he had tested it first with some other creature.

But Marcus had been impatient. Maybe this came with old age, but, given his experience in state-of-the-art electronics, this was a schoolboy error, but ironically, a schoolboy was what he wanted to be, in all but mind.