When their adopted son Nico is diagnosed with leukemia and needs a bone marrow transplant, Alice and Tomás are driven into a desperate search for a compatible donor, while concealing the truth about his adoption. With no match within the family, they are forced to locate Nico’s biological father, leading them to Cris, an unsuspecting mechanic whose life is upended by the revelation. As Cris forms a bond with Nico and becomes his only hope for survival, tensions escalate between the biological and adoptive parents. Old secrets resurface, and an unexpected love emerges between Alice and Cris, putting custody, loyalty, and the very definition of family to the test.