故事设定在一个被冰雪覆盖的乡村小镇，《佩尔蒂埃警报》聚焦于经验丰富的蒙特利尔调查员纪尧姆·佩尔蒂埃中士。当他朋友的前妻被发现遭谋杀时，他原本平静的度假就此结束。纪尧姆与一丝不苟的当地警官伊夫琳搭档，在他们展开调查并揭开惊人秘密的过程中，他们面临着与时间的赛跑。

The Missing Persons Special Unit takes on new cases.

A young man in light clothing is arrested in the street by two police officers on patrol. He is not in his normal state. He claims that he has just escaped from a dangerous maniac and leads the police to the home of his alleged attacker.