Sydney finds herself face-to-face with her long-lost mother, Irina Derevko, whose intentions for her daughter are made chillingly clear. However, Sydney manages to escape and rejoin Jack and Will in their escape from Taiwan. After arriving back in Los Angeles, Sydney continues her search for Vaughn, not knowing if he is dead or alive after being swept away by a wall of water in Taipei. Will's life is forever changed when he learns the truth about SD-6 and Sydney's life as a double agent. Also, Dixon must decide whether or not to inform Sloane of Sydney's suspicious activities. But Jack intervenes and covers for Sydney who later finds Vaughn who helps her try to track down her mother Irina who's searing for a Rimbaldi artifact called 'the Bible.'

年轻美丽的雪梨.丝斯朵拥有两个截然不同的身份。表面上她是个大学研究所的学生，但实际身份却是SD－6情报员，雪梨以为她是在为国家工作，因为SD－6 …

Sidney Bristow is a college student who has an unusual job – she is a spy working for the CIA under secret conditions where not even her friends knows what she does. When her boyfriend proposes Sydney tells him what she does for a living and her employers kill him in line with procedures. Deciding to leave the agency before they kill her too Sydney discovers that she has actually been working for SD6, an agency that is actually a shadowy criminal organisation world-wide. Sydney joins the CIA and works as a double agent to help CIA Agent Vaughn to bring down SD6. She finds that her father is the other double agent within SD6 and the pair work together. While following her missions to uncover the work of the prophetic Rambaldi she must feed information back to the CIA without blowing her cover.

西德妮-安妮-布里斯托是一个年轻充满活力的大学生，同时，也是神秘组织SD-6(CIA/中央情报局的最高秘密分支机构)的新生代情报员。几年后，当她将自己…

西德妮的母亲原是前苏联间谍，现 在则是某犯罪集团的首脑，一手掌握黑白两道许多人物的丑闻，在枪伤雪梨后以赎罪的心态向中情局投诚，并多次提供可以…

表面上，雪莉（珍妮弗·加纳 Jennifer Garner 饰）是一名普通的大学研究生，实际上，她已为名为SD6的秘密情报组织工作多年。在同男友结婚之际，雪莉决定向其公开自己的真实身份，没想到男友却因此被组织的安全人员暗杀。愤怒中，雪莉选择了“罢工”，之后亦遭到了抹杀。 　　危机之中，雪莉知道了自己的父亲杰克（维克托·加柏 Victor Garber 饰）也是和自己一样的秘密特工，并且，在背后扶持SD6的并非国家组织，而是拥有强大武力的反动分子。于私于公，雪莉和SD6都有着不共戴天之仇，她回到了SD6，但此时，雪莉的身份已升级成了为CIA工作的双重间谍，在危险和考验之中，雪莉的任务只有一个，那就是彻底铲除SD6。

Having woken up in Hong Kong, with no memory for the last two years (!), Sydney returns to Los Angeles to try to piece together the last two years of her life and discovers the fates of her friends and family: Vaughn has married thinking that Sydney was long dead; Marshall is having a baby with CIA tech expert Carrie Bowman; and Dixon is now the new division head of the L.A. office branch of the CIA. Sydney also learns the shocking fates of Jack and Sloane; the former is in CIA custody for communicating with Irina whom still is in hiding, while the latter is living in Switzerland under house arrest in exchange for co-operation with the CIA. Sydney is granted temporary CIA clearance on a case that may help her regain her memory and she meets a new enemy group called The Covenant.

克劳斯在成功抓获《尸》的同伙后返回阳炎宫。 　　然而，在那里得知的却是缇雅、莫妮卡、安妮特和爱尔娜选拔组的失踪。 　　选拔组的女孩们在度假时遇见了一位因失忆而来历不明的女孩——安妮特的母亲。 　　每个人都对重聚感到兴奋，但这却是分裂团队残酷命运的开始。 　　失踪少女的《秘密的任务》到底是什么？ 　　世界最强的间谍们、世界最大的欺骗！

动物世界景象万千，无奇不有，置身其中会是怎样的感受呢？为了一探究竟，我们派出了一组“动物间谍”做卧底。它们不但外观酷似拍摄目标，行为也模仿得惟妙惟肖。配备上先进的摄像技术后，这些动物间谍被派到了世界各地。从烈日炎炎的热带，到遥远北方的大陆。从南部海域的岛屿，到冰雪覆盖的极地。我们的间谍深入动物世界内部，展现了万千生物的蓬勃生机。有用歌声赞美美食的山地大猩猩；在海滩上集体产卵的丽龟；在河水泛滥时，到树丛中捕鱼的亚马孙河豚；能够修建堤坝与住处的河狸；为后代长途跋涉的黑脉金斑蝶；冒着生命危险到大海产卵的红蟹；能中和桉树毒素的考拉；喜食蛤蜊的大西洋海象；通过泡温泉来取暖的日本猕猴；通过晒太阳来提高自身体温的海鬣蜥；以及嗅觉极其灵敏的北极狼。

蒂姆，一个单身父亲，想要赢回他叛逆的的9岁大的儿子－马库斯的尊重和感情。为了证明他不是一个彻头彻尾的失败者，蒂姆离开他那毫无前途的工作，却意外的被军情五处招募为间谍。本剧讲述的就是这样一个菜鸟间谍的工作和生活。