Time is nonlinear

12 alien spacecrafts ('pods') land upon earth on different locations and no one can interpret the reason for their arrival because the alien language and writing is quite impossible to decipher and, also, it's uncertain do they understand anything of human means of communication. Professors and military analysts all around the world try to figure out the answer to one simple question, do they come in peace. Can't say there's that much happening most of the time of the movie, but nevertheless one of the greatest contemporary directors Denis Villeneuve has a flair for doing everything in interesting and entertaining manner.