The joy of an unexpected wedding proposal brings three best friends closer than ever, until a series of secrets are uncovered, and a dangerous obsession begins to spiral out of control.

Saskia and Alex go to extreme lengths to conceal damning lies from the past while Olivia wrestles with her life-threatening secret and Saskia seeks out comfort.

As Melanie fights for her marriage in the wake of her affair, Olivia rebounds from her failed engagement with a charming stranger, and an impetuous misstep of Saskia's catches up with her.

Melanie provokes a dangerous new rage in Jakob when she digs into his past. Olivia hides her diagnosis from those closest, while Saskia's unexpected relationship history is revealed.

Olivia's wedding has finally arrived. None of the women realise that Melanie is still in danger - Jakob is hell-bent on revenge.