The premise is excellent. Grief makes us want to hear lost voices again, and The Mimic turns that wish into a trap. Shin Rin-ah, as the mysterious girl, is both innocent and creepy, and the moments where she speaks in another person's voice are the best in the film.
Yum Jung-ah is strong as Hee-yeon, a mother who cannot let go of her missing son. Her desperation is believable, even when her choices are hard to accept, like taking a strange child into her home without telling the police.
The forest and the bricked-up cave are very atmospheric, and the director avoids cheap jump scares in favour of slow unease. An endless staircase into the cave is a striking image.
The problems come in the second half. The police play little role, a blind neighbour explains the whole backstory in one scene, and the cave finale becomes repetitive. The creature itself is less scary than its legend. Critics were kinder than audiences, and both have a point.
