The younger sibling, Tom Johnson (Locke), was an annoyance to his older sister Sara (Pope).

He soon finds out that oxygen is poisonous to the cute and fuzzy aliens, and they only breathe sulfur.

The moral shift appears to be out of character for Sara since we were first introduced to her after she was caught joy riding in a stolen car with her punk rocker convict boyfriend.

After the two siblings are successful in their moral crusade, they are transported back into the modern day ghost town from whence they came.

Tom and Sara's sour relationship heals as they drive back to their suburban home.