During an eventful summer in Harlem, fourteen-year-old Mouse and his friends fall in and out of love and search for a hidden treasure from the days of Al Capone.

While his human Elliot adjusts to his new home and stepfamily, Gizmo, an evil genius guinea pig, searches for a new evil lair where he can plot to take over the world, but Gizmo is constantly thwarted by Elliot's little stepsister Jasmine (who likes to play dress-up), Abuela (who may or may not like to eat cavies), and Wedgie (a Corgi superhero and Gizmo's nemesis).

A mother wakes up her child whose job is to play, as there is so much to do in a fun-filled day, from dancing in puddles to jumping in leaves.

As May rescues schoolchildren from bees by making them beets, and scouts from a bear by making it a beard, lasso-wielding Stu asks to be her sidekick but businesswomen do not need sidekicks, do they?

"Kiely knows she is famous! The paparazzi (her parents) follow her every move, documenting it all with cameras. It's exhausting being famous, but someone has to do it! She even gets to perform a big song at her grandfather's birthday. When she messes it up, she's worried she's lost her audience forever, but it turns out that no one is as loyal as her fans who love her"--

While Gizmo continues his quest to take over the world, Wedgie and his best friend, a micro-pig who lives next door, team up to stop him.