The movie's cast is led by Elle Fanning as Violet Markey and Justice Smith as Theodoure Finch, two teenagers struggling with mental illness who meet when they both get the same dark idea at their lowest points. Along with these two, the cast includes Luke Wilson as James, Alexandra Shipp as Kate, Keegan-Michael Key as Embry, and Kelli O'Hara as Sheryl. Rounding out the cast will be Lamar Johnson as Charlie, Felix Mallard as Roamer, Sofia Hasmik as Brenda, and Virginia Gardner as Amanda.