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.

Melanie turns stalker in a bid to save another woman from Jakob's harassment, while Olivia discovers Alex's darkest secret, and Saskia starts to spiral in the aftermath of a vicious attack.