If you want to get to know Marina Ali-O'Connor, you need to know three things:

One, despite her name, Marina is secretly afraid of the water.

Two, she wanted to be one of the Oldest Siblings, but is stuck smack dab in the middle.

Three, she's pretty certain she's the Extra Ali-O'Connor kid--the forgotten one.

When Boom, a budding filmmaker exactly Marina's age, moves in across the lagoon, she decides that Marina's quest to become someone's favorite Ali-O'Connor would make a perfect documentary. But when each plan goes a little bit wrong, Marina begins to wonder if she'll ever feel like she belongs, or if she'll always be lost in the middle.