They say keep your friends close and your enemies closer.
Molly has always found her ex-landlady, Mia, fascinating. She's a quaint, enigmatic old dear who tells enchanting stories of her decadent youth. Alongside her outrageous gay best friend, Simon, who she's known since uni, Molly has come to regard Mia as one of her closest confidantes.
So when Mia is widowed, and worse, her beloved dog, Heathcliffe, dies, it is naturally Molly who comes to her rescue, offering her the chance to live with her and her husband, Daniel.
But sometimes it's hard to tell the difference.
However, instead of the surrogate grandmother she wished for, Molly discovers Mia is a cuckoo in the nest - a rather elderly femme fatale. She overhears Mia making a play for her husband - which would be ridiculous if Daniel wasn't falling for Mia's lies. It seems that underneath her sweet old lady exterior, Mia's merely been biding her time, waiting until Molly had a life worth stealing.
With Simon's help, Molly is determined to fight back. But can she trust Simon, even? She's seen the lustful sparkle in his eyes when he looks at her handsome husband. Sometimes it seems best friends can share a little too much.