Franziska, Meike, Samira, and Nadine have been friends since childhood and now live as neighbors in semi-detached houses on a cul-de-sac. Julia, new to the neighborhood, wishes to join their close-knit circle. Unbeknownst to her, the four harbor a dark secret—shared responsibility for a body, not in the basement, but at the bottom of a lake. The lake's water level is dropping alarmingly due to Steinert's construction site, threatening to reveal their hidden past. Tensions rise as the friends frantically try to keep their secret buried, each grappling with the fear and guilt it brings to their seemingly perfect lives.

As the deadline for her dissertation looms two days away, Julia finds herself under immense pressure with her family arriving specifically for her big moment—yet all she has is a foreword. Meanwhile, Samira learns that two construction workers are experiencing respiratory issues. Seeing an opportunity, she speculates that neglecting safety regulations could serve as grounds to halt construction. Determined to uncover toxic substances, the four friends decide to infiltrate the golf course construction site, embarking on a daring mission to find answers.

Meike is determined to run for mayor and sees the Honey Blossom Festival as the perfect opportunity to gather support. However, her plans hit a snag when she encounters the current mayor Fischer at the event. Undeterred, she continues her quest to raise funds to settle her tax debts. Meanwhile, Samira faces a different challenge as she discovers a lump in her throat and desperately tries to secure a doctor's appointment. As the pressure mounts, both women must find ways to navigate their personal and political struggles in their small town.

Mona's involvement successfully halted the construction of the golf course, much to her friends' relief. However, another crisis looms on the horizon. Meike's necklace has resurfaced in a secondhand shop, raising questions and concerns as Nadine claimed she had disposed of the necklace back then. This unexpected discovery threatens to unravel past secrets, testing the bonds of friendship once again as Meike and her friends grapple with the unfolding mystery.

Franziska is on cloud nine, reveling in a passionate affair with Lukas. Her bliss is soon overshadowed by suspicion when evidence suggests Lukas might be the author of the anonymous threatening letters she's been receiving. To divert Mona's attention from the situation, Nadine suggests she conduct an interview with Meike, who is running for mayor. This unexpected twist intertwines personal desires with hidden motives, creating a gripping narrative of mystery and intrigue. Franziska seeks the truth, but the contradictions in her love life may lead her to unexpected revelations.

Despite her lack of a diving license and never having dived with an oxygen tank, Samira must take the plunge, and her friends are determined to assist. The challenge happens on the very night Felix plans a romantic setting to propose to Julia once again. As emotions and chaos intertwine, the friends navigate a spontaneous underwater adventure, balancing their support for Samira with the unfolding romantic drama between Felix and Julia, who are caught unaware of the underwater mission. A night meant for love transforms into an unforgettable escapade of friendship and unexpected bravery.