The trailer shows a family, with Lupita Nyong'o and Winston Duke as the parents, taking their two kids to the beach for a vacation. Everything seems fine, until the son spies a strange person standing on the beach in full winter clothing...with what appears to be blood dripping from his fingertips. No, this is not your normal summer family getaway.
Then a creepy family of four show up in their driveway and just stand there, creepily. The trailer reveals that the family is them, or some alternate universe versions of them, who have come to kill. How do you fight an enemy who not only knows who you are and how you think but literally is yourself?