It's Valentines Day and everything's changing in the Casson household.
Indigo sets out to do something special to win over Sarah and ends up organising the Valentines Day disco and playing cupid. Saffy has a strange new boyfriend who teaches her all about the stars. Sarah falls very ill - when she can no longer laugh it off Saffy gets scared. And Caddy has fallen in love and is getting married ... but not to Michael.
With a wedding to plan everything's a little crazier than usual in the Casson household. Especially as the only one who seems to be happy for Caddy is Bill.
But it's Permanent Rose who's taking the news the hardest. She made a BIG promise to Michael - how is she going to keep it now?