Prime Video has one of the best film libraries of any streaming service. But if you don’t watch the movie you want to see right away, you might never get the chance. October 1 is the official kickoff of spooky-movie season, but this year, we simply could not wait. On the last day of September, my wife and I watched the 2013 throwback slasher, You’re Next, one of many horror movies available to stream that I’d compiled into a seasonal list.