Mike Brady has to go to New York on business and as a special surprise he tells the entire Brady Bunch (including Alice) that he's taking them with him! They're going to be staying at the home of an old friend of Mike's (who also has a 16-year-old daughter - just the right age for Greg).
But, what promises to be a fun-filled trip starts to turn into a dangerous adventure the night before the Bradys are to leave when their house is robbed. Then, they're followed to New York by mysterious strangers!
Along the way, Peter turns photographer and takes some dangerous pictures and then gets lost (with Jan) in a dark, lonely park with strangers in pursuit! Greg falls in love with a beautiful girl and the mystery deepens as the Bradys are robbed again!