Nadine Walsh's summer garden party is in full swing. The neighbors all have cocktails, the catered food is exquisite--everything's going according to plan.

But Nadine--devoted wife, loving mother, and doting daughter--finds herself standing over a dead body in her basement while her guests clink glasses upstairs. What happened? How did it come to this?

Rewind to that morning, when Nadine is in her kitchen, making last-minute preparations before she welcomes more than a hundred guests to her home to celebrate her mother's birthday. But her husband is of little help to her, her two grown children are consumed with their own concerns, and her mother--only her mother knows that today isn't just a birthday party. It marks another anniversary as well.

Still, Nadine will focus just on tonight. Everyone deserves a celebration after the year they've had. A chance for fun. A chance to forget. But it's hard to forget when Nadine's head is swirling with secrets, haunting memories, and concerns about what might happen when her guests unite.