Two lonely strangers each land a job working for a mysterious spy agency that offers them a life of espionage, wealth, world travels, and a beautiful brownstone in Manhattan.

For their part, they must each assume a new identity in an arranged marriage as Mr. and Mrs. John and Jane Smith. The new couple now need to navigate high-risk missions while also facing a new relationship milestone. Their complex cover story gets even more complicated when they realize they have feelings for each other.