When you open the box, the secrets come to light...

Natalia García is going to celebrate her birthday at her parents' house with Carlos, her partner. However, the night before, she picks him up from the hospital where he is doing his internship, and he comes out with scratches on his face. Before the celebration, Natalia finds a box in her room filled with objects, including a broken crystal. This triggers a series of memories that unfold alongside the celebration, making her question what other things Carlos has hidden from her and who he really is.