As befits a movie titled Detour, writer-director Christopher Smith took a circuitous route while plotting his neo-noir about a grieving law student with dark suspicions about his shady stepfather.

Speaking to EW at the recent Tribeca Film Festival, Smith said he initially drew inspiration from thrillers such as Disturbia (which is itself partly inspired by Rear Window) and Strangers on a Train.

“Before I knew it I’d come up with this split narrative, and then I had the twist,” said Smith, whose other credits include Black Death and Triangle. “I had this whole mathematical formula before I had any characters or story … and then I spent four years trying to think of what characters populate it.”

Those characters would come to include Harper, the naive protagonist played by Tye Sheridan; Johnny, a volatile grifter played by Emory Cohen; and Cherry, a stripper played by Bel Powley.

Watch the video above for more from Smith, Sheridan, and Cohen.