MEN IN BLACK (1997) Stream on Netflix. Rent on Amazon, Google Play, iTunes, Vudu and YouTube. What makes this late ’90s favorite such an effective twist on the alien encounter genre, Janet Maslin wrote in her review for The Times, is that it portrays the human-alien relationship as comically undramatic. The existence of extraterrestrials is kept secret from the public, but for members of the government agency tasked with tracking them, it’s old news. Will Smith plays a New York City police officer who joins the organization after impressing a Men in Black agent (played by Tommy Lee Jones) with his handling of an alien encounter. The partners are quickly drawn into a conflict when a villainous buglike creature illegally arrives on Earth.

OPERA (1987) Stream on Mubi. The streaming service continues its Halloween season celebration of Dario Argento’s giallo horror films, a subgenre he helped develop in the ’70s, which combines murder mystery with other genre elements like stylized gore, transgressive eroticism and the supernatural. This 1987 movie tells the story of Betty (Cristina Marsillach), a young opera singer who is being stalked by a brutal murderer after she assumes a major role in an avant-garde production of “Macbeth.” As the bodies pile up, Betty starts to suspect the killer is connected to the murder of her mother. Blood flows as the plot twists and turns to the very end.