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.

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。

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.'

『间谍过家家』第2季动画最终话结尾预告「SEE YOU NEXT MISSION」

〈夜帷〉为完成任务向〈黄昏〉求助伪造专家遭拒后被安保局追捕，在保护同伴中成功脱身。阿尼亚于学校机智救下达米安，展现成长。〈黄昏〉的过往揭晓——他因战争失去家人而投身情报工作。〈对奥科〉在演唱家丑闻事件中化解社会危机，新人特工亦成长。阿尼亚因校车误点与亨德森老师互动，受到鼓励而更努力学习。 约尔救人被卷入妇女会排球赛，结识达米安之母梅琳达，萌生成为好母亲的想法；劳埃德则视此为接近德斯蒙的契机。医院中，劳埃德因太受欢迎被上司嫉妒陷害，甚至遭举报为间谍。尤里探望约尔，与劳埃德展开家务比拼却屡战屡败。 校外教学途中，阿尼亚的班级遭遇巴士劫持。她利用读心术与同学合作传递求救讯息，却被装上炸弹项圈。她发现项圈无法爆炸却引发恐慌，达米安为护她也被绑。警方包围巴士，劫匪以达米安为人质，亨德森试图缓和局势。特工成功解救另一辆人质车，夜间攻坚在即。阿尼亚以读心术误导劫匪、赢得同情，却在关键时刻被挟持，幸得援军出现。事件落幕，学生获表彰，达米安体会到家庭温暖，梅琳达亦现身支持。阿尼亚因受欢迎而自满，与达米安的竞争转为打趣式友谊。 事后，随车教师汤玛士受梦魇困扰，求助劳埃德心理咨询，揭露内心秘密。西尔维亚收养猎犬，与劳埃德携犬参赛，增进情谊。约尔酒后误会夫妻关系，引发小摩擦。与此同时，尤里与劳埃德分别接获紧急任务，〈对奥科〉与情报局同时展开行动。间谍惠勒窃取国家机密，〈黄昏〉设陷引出内鬼并伪装潜逃。尤里凭直觉追至下水道，与伪装成自己的〈黄昏〉正面交锋，兄妹与间谍间的命运对峙正式揭开序幕。

“少年007”系列剧集《少年间谍》(Alex Rider)正式获续订第三季，本季故事改编自Alex Rider系列小说第五部《毒蝎党》(Scorpia)，依旧由Guy Burt担任改编。