Curvature(2017)

"Changing the past changes everything"

Overview

Helen tries to cope with the recent death of her husband, a scientist who killed himself right when he was on the verge of successfully completing the invention of a time machine. One day, she receives a phone call, and a voice suspiciously resembling her own voice warns her that she’s in danger. Is it possible Helen has time travelled? And what could have led her to do something like that?