Stephen King’s 1986 horror novel It told a story of small-town children who are menaced by a demonic clown in the late 50s and then reunited 27 years later when the curse returns to their hometown; this big-screen adaptation dramatizes the childhood section alone, moving the action up to the late 80s and branding it “Chapter One” in the closing credits to drum up interest in a modern-day sequel. Director Andy Muschietti models the movie on Rob Reiner’s Stand By Me (1986), another King adaptation about young pals, and his talented teen actors (especially Sophia Lillis, Finn Wolfhard, and Jeremy Ray Taylor) deliver some good moments as the clique of grade-school losers, who begin to compare notes about their horrible visions and discover that a supernatural force invades the town periodically to prey on children. The serious dramatic themes ring hollow, however, leaving only the paperback boogety boogety to justify the Oscar-bait running time.