A better way to reveal the climax surprise: Instead of cutting away too all that lock-box backstory, we watch Ivy climb over the fence and see her, in a tight shot, fall in the gully on the other side. Then as she crawls up the incline, still in a tight shot, we zoom in on one hand as it reaches the edge of the pavement, then pull back, and back, and back to reveal...modern day.

Then we can go back to the lock box to fill in the blanks.

That would have had a much greater punch.