In The Secret She Keeps, Meghan doesn't know Agatha, but Agatha knows Meghan. Two women from vastly different backgrounds have one thing in common: explosive secrets that could destroy everything they hold dear.

Two women have a chance encounter in a supermarket, in an affluent Sydney suburb. They are the same age, both heavily pregnant and due at the same time. Meghan (Jessica De Gouw) is a glamorous influencer on the rise, with an ambitious television sports reporter husband Jack (Michael Dorman), while Agatha (Laura Carmichael) works in the supermarket as a shelf stacker.