Sky has undergone a transformation and in the process has triggered a countdown that nobody is able to stop. Sarah Jane and Sky end up being trapped between the alien war fought by Metalkind and Fleshkind. Clyde and Rani attempt to prevent the biggest bang the world has ever seen.
Elenco: Elisabeth Sladen , Tommy Knight , Alexander Armstrong , Daniel Anthony , Anjli Mohindra , Yasmin Paige .