When Erica French opts to keep the baby she conceived in high school, she never dreamed that one day she would be fighting for custody against the child's father, Scott Stone. Scott Stone initially fought for custody when Erica threatened to cut off his access to their daughter. Scott continues to try to be a part of his daughter's life, but when Molly first breaks her arm at the playground then Scott's mother finds mysterious bruises on her granddaughter, Scott again fights for custody of young Molly, and this time he wins because the court feels his family can provide a more stable environment for Molly than a public daycare can.

伦敦市中心发生的致命爆炸摧毁了美国大使凯特·怀勒（凯丽·拉塞尔饰）的世界。凯特努力重建破碎的生活和四分五裂的团队，而她最担心的事情也随之而来：这场导致她被派往英国的袭击并非来自敌对国家，而是来自英国政府内部。在追查真相的过程中，她唯一真正的盟友是她的准前夫哈尔·怀勒（卢夫斯·塞维尔饰）— 他不仅活得好好的，还参与了很多事情。凯特面临着岌岌可危的婚姻、与英国外交大臣奥斯汀·丹尼森（大卫·吉亚西饰）的复杂关系，以及来自副总统格雷斯佩恩（艾莉森·珍妮饰）的一次威胁性访问。
豪宅、国家机密、叛国罪、下午茶 — 由创剧人、剧集主管兼监制黛博拉·卡恩执导的荣获艾美奖提名的剧集《头号外交官》推出第二季。贾尼丝·威廉斯、艾利克斯·格雷夫斯和凯丽·拉塞尔担任监制。演员阵容还包括阿丽·安、罗里·金尼尔和艾托·艾桑多。

讲述在一场国际危机期间，这名美国外交官既要应对身为驻英大使的重任，又要处理与政坛明星之间紧张的婚姻关系。