The Final Mind-leap

A brilliant scientist from a 5-dimensional universe carries out an experiment in our own 3-dimensional world seeking to improve brain power. This takes place in pre-historic times but a mishap occurs which results in a total of 5 cases of enhanced brain power - mind-leaps - taking place, spread out across a vast period of time. The story explores each of these mind-leaps culminating in a clash between the last two beings to receive them. How will the enormous power they acquire resolve itself in their conflict?