故事围绕着3对不同婚龄的夫妻，三对夫妻的婚姻关系都因宠物的介入有所变化。崇良（张奕恺饰）与雯豫（周智慧饰）是一对新婚夫妻，但两人之间总有一只小三，就是与雯豫相伴十年的爱犬Kito。结婚七年的嘉男（蔡琦慧饰）与毅杰（谢俊峰饰）因领养了一只流浪狗Picasso竟加剧了夫妻间的矛盾。老 夫妻自光和美岚（林茹萍饰）的生活早已是寡淡无味。直到Picasso的介入，两人的婚姻才再度掀起涟漪。
他们在一次意外事件中相识，本以为只是彼此生命中的过客，却在不断逼近的危险与真相中，被迫站到同一阵线。当爱与责任、真相与救赎交织，他们必须在“刀刃之上”寻找各自的答案。
Already on opposite sides of Michael Hewes's custody suit against his mother, Patty Hewes (Glenn Close) and Ellen Parsons (Rose Byrne) prepare to face off in court after a cyber-hacker's revelations about insider trading expose damaging personal information that push an informant over the edge.
An Argentinean intelligence agent infiltrates the Jewish community to gather information that is then allegedly used to perpetrate two of the worst terrorist attacks in Latin American history, leaving over 100 dead.
A rootless genius, Iris Nixon, steals an enigmatic code from a charming philanthropist and disappears. A tense countdown ensues as she races to unravel the code's mystery.
