Peter and Bronny Taylor go on a trip to the Grand Canyon with their daughter, Stephanie, and Mikey, their autistic son. Mikey discovers a small cavern, where he finds rocks with glyphs on them. He takes the rocks, keeping a secret untold. When the Taylors return home, strange things begin to happen..
There’s a scene where the dad opens up an e-mail from the mom, with a YouTube-looking link (watch?v=FDhoqY1grJY). If you paste that video ID to YouTube, it redirects to The Darkness (2016) trailer.