Which Sister drops a curveball?

Tonight’s episode of Sisters has a lot of surprises.

The curve balls keep on coming for Julia (Maria Angelico) when the arrival of another possible sibling, Casey (Emily Barclay), tips her over the edge.

Although Casey’s claim to the Bechly name seems suspicious, Julia decides to give her the benefit of the doubt, much to Roxy’s (Lucy Durack) frustration.

Edie (Antonia Prebble) attempts to recruit Roxy’s parents, Ron (Roy Billing) and Diane (Magda Szubanski), to the class action without her sisters’ knowledge. Will they take the lucrative bait dangling in front of them?

While Julia turns to Tim (Dan Spielman) in her hour of need, Edie continues to feel lost in her marriage and struggles to resist her growing attraction to Amanda (Zindzi Okenyo).

Sisters airs 8:30pm tonight on Ten