在这部怪物恐怖片中,青年建筑师Ray（方中信 饰）带妻子May（舒淇 饰）及5岁儿子子路(谭竣浩 饰)搬进新家的翌日傍晚，就有怪事发生，May带着子路在天台花园玩耍时，看到子路被强大力量离奇扯出天台，坠楼失踪。接着，May又频频听到小孩寻找母亲的哭叫声，更恐怖的，是家中无论子路的玩具还是衣衫都先后离奇失踪。 在警察的帮助下，Ray和May知晓导演这一切的，是躲藏在他们背后的神秘“怪物”（林嘉欣 饰）。而在与“怪物”争夺儿子的过程中，Ray和May渐渐了解到，神秘“怪物”在丑陋可怖的外表下掩藏着一个不为人知的辛酸故事。
A family moves to a new flat on a big building. They get to know the building was erected over a burnt slum, when lots of poor people died in a non accidental fire set by the constructors. Soon their only child, a boy, is kidnapped by what seems to be a strange humanoid creature lurking in secret through the ventilation and trash pipes that connect everywhere around. As the father is heavily wounded by the creature and goes to hospital, the mother undertakes the investigation the police should do. But what she will discover will put herself in conflict with her own beliefs as a mother.
階級矛盾如何調和——小論《怪物》。沉重的母爱。《怪物》：暴力──大廈發出聲音，或，聲音撞向大廈。怪物不怪。《怪物》：象徵秩序的虛幻。《怪物》：一个女子的终极悲情。令人疯狂的痛，令人勇敢的爱。无私的爱，自私的爱。李 嘉 欣 的 电 影 人 生。我爸爸说。
