In EN LAS SOMBRAS, Mari narrates the mythological story of Xenia and Luz, who journey to take the trial of the gods. If successful, they will save their mother and become gods themselves. As the play progresses, there are hints that the world onstage is not exactly as it seems. The first test that the siblings must face is to escape a room made of ice. Then the children must solve a series of seemingly impossible riddles. Finally, they are detained in a room, surrounded by the bones of dead children and simply told to survive. By the end of the play it is made clear that Xenia and Luz are being detained along the U.S./Mexico border and the audience has been seeing the world through their eyes as they try to cope with the horrors of their situation.