“She loved mysteries, and so she became one,” narrator Quentin (known as Q, and played by Nat Wolff) tells us in the teen-dream drama “Paper Towns.” He’s speaking of his neighbor and fellow high-school senior Margo Roth Spiegelman (model-turned-actor Cara Delevingne, looking a tad old for high school) who, after a late-night revenge spree, disappears from their Orlando suburb just before graduation. Her parents have no idea where she’s gone, but Q — caught up in the romance of it all — finds clues that she’s left behind, and makes it his mission to find her.
As befits a teen movie, “Paper Towns,” based on the YA novel by John Green (“The Fault in Our Stars”), is all about the drama — unrequited love, young romance, a disappearing heroine, a perfect prom night, the nostalgia felt in the final weeks of high school and what one young character calls “the lastness of it all.