Lucy and Wendy are on the verge of falling out badly. Wendy points out that she's always inviting Lucy round to her house, but Lucy almost never invites her back in return. Is Lucy ashamed of her? Of course, what Lucy is really worried about is that Brian and Sophie might give themselves away as aliens. But in order to save her friendship, Lucy makes a plan. She gets Brian and Sophie to agree to try to be normal so Wendy can come for a sleepover. But it isn't exactly easy for Brian and Sophie to be normal... Meanwhile, when Josh tries to raise some extra cash by charging for odd jobs around the house, Brian and Sophie begin to question why some jobs are paid and others - like housework - aren't. The best things in life may be free, but in this house everything turns out to have a price. Mel turns her back on all this materialism and vows to donate her old toys to a children's home. But she soon finds out that giving away things from her past isn't that easy.