Matthew and Albertine have separated. While she study in Cambridge University, Matthew still working in his project, but when Albertine exposes accidentally to Chocky to an evil man called Doctor Liddle who discovers the Chocky's existence, the danger begin because Liddle believes what Chocky is an intruder, a threat for the humanity and the first step for a great invasion. Chocky returns to help Matthew and Albertine, fight against Dr. Liddle and reveal finally the secret of the cosmic energy.