The quest to live forever has captured our collective imagination for centuries, from ancient texts in the time of Alexander the Great to current sci-fi movies. But as a scientist notes in the trailer for "Selfless," "Immortality has some side effects."

That proves to be quite the understatement. In the movie, Ryan Reynolds.

But after the seemingly successful procedure, things start to go awry (natch), as Reynolds' consciousness battles that of Kingsley's for ultimate control.

"Selfless" opens in theaters this summer.