After the events of season 3, the Casagrande and Chang families get evicted from their home in Great Lakes City, and they end up moving to Royal Woods where they have to share homes with the Louds and McBrides. Desperate to get their home back, Ronnie Anne convinces her familia and best friend Sid to travel to Rio de Janeiro to find a valuable treasure. But little do they know, someone else wants the treasure for the wrong reasons.