Awkward introvert Peter has worked in the same place all of his life. His co-workers know him well enough to understand that Peter has no intention of ever helping them cover a shift. So when Shelley needs the night off to go to a party, she tries her luck ultra-forcefully. Although Peter still declines to help her out, her insistence backs him into a corner that he can only get himself away from by coming up with an even bigger whopper of an excuse than normal. And that excuse is that introverted, no-pals Peter is too busy with his made-up friends going to an even bigger party than the one Shelley will be missing out on. Luckily for Peter this does get him out of covering a shift but unluckily for him Shelley is now expecting to see proof of this mad night out. The result is a real party that's as "mental" as Peter made out, but for all the wrong reasons.