In “Muzzle: City of Wolves,” Jake Rosser (Eckhart), haunted by PTSD from his days as a K-9 officer, endeavors to lead a peaceful life with his family and retired K-9 companion, Socks. But the tranquility quickly dissolves when a ruthless gang targets them in a brutal attack. Determined to protect his loved ones, Jake and his new K-9 partner Argos delve into a violent underbelly of crime where Jake confronts corrupt officials, uncovers a perilous drug trafficking ring and battles his own inner demons.

　　20世紀70年代，在日本中小學生中間流傳著這樣一個恐怖的傳說：放學獨自走到公園附近時，會遇到一個帶著白色口罩、穿紅色風衣的女人。遇到路過者，她會摘下口罩，露出裂到耳朵的恐怖大嘴，問對方“我漂亮嗎？”如回答不漂亮，她會將對方毀容；若回答漂亮，她就將對方變得和自己一樣；如果逃跑，她會以極快的速度追上。這個女人的名字就叫：裂口女。　　各學校一時間人心惶惶，男女學生們都怕碰到這個可怕的女人，而大人們卻對這個謠言嗤之以鼻。但隨著一場不詳的地震發生，裂口女終于到來……

　　Joseph Fulton, a well-regarded fifty-eight-year-old director of romantic comedies, wants to become assistant groundskeeper at a local cemetery. He wants to work outdoors and be close to nature. Meanwhile, he thinks it’s important to have his last will and testament drawn up. But his highly dramatic actress girlfriend thinks he must be dying and that he is just too brave to tell anyone. The rumor spreads and soon everyone he knows—and some he doesn’t—are crowded into his small apartment to say their last farewells.

　　三年前的 8 月 31 日，突如其來的“侵略者”，—艘巨大的“母艦”降落至東京上空，世界似乎迎來了終結……在那之后，絕望融入了日常生活，巨大的圓盤飄浮在上空的世界持續到現在。小山門出、中川凰蘭兩個高中少女，在這個走向終結的世界中，揮灑著自己的青春時代。