Back at Alexandria, with their friend Curtis Pepper visiting, Kensy and Max are enjoying the school break. Especially when Granny Cordelia surprises them with a trip to New York! It's meant to be a family vacation, but the twins soon realise there's more to this holiday than meets the eye.

The chase to capture Dash Chalmers is on and when there's another dangerous criminal on the loose, the twins find themselves embroiled in a most unusual case. They'll need all their spy sensibilities, along with Curtis and his trusty spy backpack, to bring down the culprit.