Liv, Maddie and the rest of the Rooney family are excited to start their new life in California. As the school year begins, the Rooney's cousin, Ruby, returns home from a summer trip. Excited to have "sort of" siblings, Ruby can't wait to finally be a sister but finds herself in the middle of a sister-fight between Liv and Maddie. Meanwhile, Joey and Parker attend their new Science and technology school and their experience is not what they expected.

Liv takes Ruby to a spooky dinner and runs into an old acquaintance and Maddie comes face-to-face with the real-life spider-sprayer. Meanwhile, Parker and Joey must convince their classmates to celebrate Halloween.

Joey is nervous when he's invited to perform stand-up comedy at a local restaurant. Parker finds himself in a predicament.

Joey's popularity at school is threatened when an old nemesis from Wisconsin returns and Maddie feels the need to keep a close eye on Parker's new friend.

When Maddie and Josh start hanging out again, Joey feels awkward by their rekindled friendship. Meanwhile, Parker and Val find themselves in a jam when competing for a coveted finalist spot in the Mars Madness competition.

When Maddie and Willow discover that one of their acquaintances is homeless, they set out to help him. Meanwhile, Karen gets discovered by a modeling agent, and Joey and Parker attempt to sneak into a movie.

Liv undergoes vocal surgery and is unsure if she'll ever be able to sing again, so Karen and Maddie call in reinforcements to help. Meanwhile, Parker and Val are surprised by their competition in the Mars Madness finals.

After exciting opportunities arise for each of the Rooney children, their summer plans are thrown into jeopardy.