This movie had so much potential, even until close to the end. Sadly it missed the mark. The character who played the chemist who made the drug was worthless in the plot other than to be a tool to explain what the drug was. He didn't need to be supposedly killed and have that be the end of story for him.
Who were the people he was interacting in the past with, himself? Those characters were also wasted as being nothing other than "someone from time period" again, lost opportunity for a better story.
And rather than just hold the girl to take her back why give her a pill? Does it even take you back like that? This was never described.
The ending took the wind out of my sails. High hopes, but no bueno. jr