Sarah, Robert and their friends are superhumans - their incredible powers have made them an unbeatable team. But now they face their deadliest battle... They're up against the Entity, an alien of immense power who is hell-bent on enslaving humanity. Its army of unstoppable killing machines is marching on London programmed to destroy... and if London falls the world will be next. As the earth's last line of defence, can Sarah and her team stop the enemy invasion?