During spring break, Cody (Cole Sprouse) and Zack (Dylan Sprouse) are approached to join the Gemini Project, a high-tech research center studying the dynamics between twins. Shockingly, they find themselves interconnected in a way they've never been before: when one twin experiences a sensation, thought or feeling, the other twin does, too. While this newfound revelation helps the boys see eye-to-eye for the first time, it puts them in more danger than they could have imagined.