Former London constable Nicholas Angel finds it difficult to adapt to his new assignment in the sleepy British village of Sandford. Not only does he miss the excitement of the big city, but he also has a well-meaning oaf for a partner. However, when a series of grisly accidents rocks Sandford, Angel smells something rotten in the idyllic village.

一名迫切希望提升社交媒体评分的女性，幸运地受邀出席一场奢华婚礼，然而此行却未如预料般发展。

本集根据《波西米亚丑闻》改编。正当 莫里亚提和夏洛克处于生死相搏之时，莫里亚提的手机响了，他接到了一个神秘的电话，不得不放弃和 夏洛克的博弈，而电话的另一头，一个妖娆女人的手出现在画面中，她手上似乎掌握着莫里亚提十分想要的东西。

在偏僻的冰雪荒野中，两个男人在小木屋里娓娓道来三个发生在圣诞佳节期间，互有关连的科技失控故事。

失去爱人的玛莎十分悲伤，这时她得知有一种新服务可以让人们与已故的人保持联系，因此她决定一试。

Over the last ten years, technology has transformed almost every aspect of our lives before we've had time to stop and question it. In every home; on every desk; in every palm - a plasma screen; a monitor; a smartphone - a black mirror of our 21st Century existence.