The sexy, sophisticated drama Mistresses is back for a final series. But all has changed as Katie, Trudi, Siobhan and Jessica are no longer friends... The drama opens as Katie calls the girls together having not seen each other for months. But what could have caused these friends to split? As Trudi, Siobhan and Jessica join Katie, the drama moves back to five months earlier to reveal what happened. Back in the present, when one of the girls reveals a secret she has been hiding will they see that they're better off with rather than without each other?