I've been a fan of Ethan Hawke for 38 years, and I was sailing along with First Reformed through the dramatic turn but disconnected in the last fifteen minutes when the storytelling went off the rails. The protagonist gets an idea that is certainly dramatic, but doesn't first his character or backstory. It simply makes no sense and when the screen went to black for the credits I actually thought there was a projection malfunction! The abrupt ending wasn't challenging, it was stupid and I felt used. I do not expect or want The Sound Of Music with every film; I can go with dark as long as its believable and I care. The last fifteen minutes of First Reformed were neither.
Review of First Reformed
