A silly, pulpy mystery entirely sure of its own conceit, “Drop” combines tech paranoia and the looming specter of abuse to create something surprisingly taut and entertaining. Directed by Christopher Landon — best known for his involvement in the “Happy Death Day” and “Paranormal Activity” movies — the film’s complicated setups are executed with a deft and capable hand. Although set in a fine dining establishment, it’s a junk-food thriller fried to near-perfection, balancing the tensions of kidnapping, conspiracy and murder with those of a nerve-wracking first date. It’s crisp and delicious.

After a hair-raising prologue involving a couple pointing guns at one another (a scene whose purpose clicks into place much later), “Drop” gently introduces its protagonist, widowed mother Violet (Meghann Fahy), as she prepares for her first date with Henry (Brandon Sklenar), a handsome photographer she’s been speaking to online. Her snarky, supportive sister Jen (Violett Beane...