
Alan and his daughter Maria discover some human skin at the house of Luke's fake parents, alerting them to the presence of the Slitheen. Clyde sees Sarah Jane return to the attic and give Smith the headset, but his attempts to warn are unheard. However, he does manage to transmit his warnings onto Alan's laptop in the form of an instant message. He rushes round to Sarah Jane's attic to spread the word, just as Smith shows his true colours by firing off laser bolts at them.
Luke's telekinetic powers are fully displayed at Pharos in front of the Slitheen, enabling him to escape and head back to the refuge of Sarah Jane's home. Unaware that Mr Smith is now evil, he is soon in his clutches and the dastardly plan to use the young lad's powers to revive the rest of the Xyloks – buried under the earth's surface - is unveiled. Clyde is returned to the action after Smith claims to show mercy.
Sarah Jane, Alan and Maria – armed with vinegar, courtesy of a chip shop – confront the Slitheen at Pharos. After a stand-off, Sarah Jane compels the Slitheen to switch sides after they realise they will be destroyed too. For Mr Smith is using Luke's powers to pull the moon onto a collision course with the Earth. The origins of Mr Smith are revealed, as Sarah Jane remembers how he first came into her possession as a crystal that started to communicate with her laptop and effectively built itself.
Using the Slitheen's teleporter, Sarah Jane and the gang quickly return to the attic, where she unlocks a vault and sets K-9 loose on the computer with the metallic mutt's laser. They unleash a computer virus, that software expert Alan has brought over, into Mr Smith and he is reprogrammed.
Order is quickly restored, with the moon returning to its position and K-9 trundling off to keep tabs on the black hole. They all watch as the Slitheen spaceship flies back across the night sky.





