In the latest episode of "The Simpsons", titled "Paths of Glory", it seems Lisa and Bart will find a sociopath's notebook and Bart will get obsessed about it.

CLICK HERE to watch what the mystery behind the notebook is and who this sociopath is.

According to the synopsis of the episode, Lisa tries to better the reputation of Springfield's first female inventor by searching an asylum for her first invention. While in the asylum, she and Bart find a sociopath's notebook, causing Bart to take the notebook home and pretend to be the sociopath who wrote it.

Lisa is determined to establish herself as the first inventor of the town and her desire has been fuelled by Homer mocking at her. Hence, she has vowed she will return home only if she makes a significant invention.

However, it seems Bart senses something fishy and stalks Lisa. Soon, they find themselves in an asylum where Bart finds a sociopath's notebook. Though he doesn't tell Lisa, it seems the sociopath is known to them.

Lisa soon notices Bart has become addicted to the notebook as he keeps writing in it all the time. To her horror, she soon realises he is developing some of the sociopath's traits. She believes the notebook has some supernatural powers that have possessed Bart.

In the previous episode titled "Lisa with an 'S'", when Homer lost $5,000 at a poker game with Broadway legend Laney Fontaine, the only way he was able to settle the bet was if he loaned Lisa to Laney for a month.

Afterwards, Laney turned Lisa into a showbiz kid and Marge and Homer feared they had made a mistake letting her go. So they headed to New York to get her back.