Inexperienced travelers and introverts Olivia Haines and Ron Whittaker decide to take their honeymoon in Mexico aboard the cruise ship the Pan Americana. They agree to change their behaviors while on vacation and become more social with no idea what this extroverted performance might cost them. They quickly befriend several of their odd shipmates.

Theres the loud mouth heiress who wants to run their lives and her nemesis, Alan Paxton, who likes to make her rich life miserable. Theres a retired Episcopal priest and his wife. Finally, Mallory Holmes: a blind and deaf young man with a frigid wife. These odd new friendships flounder, however, when Alan ends up murdered, and Mallory claims hes the perpetrator.

The passengers arrive together back in Los Angeles, where the murder case unfolds. Rons cousin takes the case, despite Mallorys insistence of his own guilt. Olivia and Ron are starting to regret their decision to meet people, but even they believe Mallory is innocent. They take it upon themselves to find the real killer, and no one will be more surprised by the truth than the newly married couple.