Watch The Demon's Waltz (2021) HD Full Movie Free on solarmovie.do. Watch The Demon's Waltz (2021) online free. Becca, a private investigator, is hired to look into the origins of a viral TikTok Challenge that ha...Becca, a private investigator, is hired to look into the origins of a viral TikTok Challenge that has haunted and caused the deaths of several people. The deeper she digs into the mystery, the more she realizes there is a very real evil lurking behind the scenes.