help! sci fi traveling back in time

[Budvar]

hello looking for - sci fi about traveling back in time and chasing some villain to the point of beginning. travel was very heavy on energy and more to point of beginning the more energy you needed. for travel there was some spheric alien vessel and main character had to sacrifice aome of his vital energy to travel.

thank you

[Michele]

was the villain a personal enemy, or a cultural, political, religious etc one? do you recall the nature of his villainy? was the villain an alien, or were they a side complication?

[Lobstergirl, au gratin]

Budvar, you must add plot details to your topic header. We have thousands of members searching for sci-fi time travel. Use the little edit link.