Anina Yatay Salas is a ten-year-old girl who does not like her name. Each part is a palindrome, which means it reads the same both forwards and backwards. Her schoolmates are always teasing her about this, especially Anina's arch-enemy Yisel, who Anina sees as an "elephant". One day, Anina and Yisel get into a playground skirmish, so the school principal disciplines them with a weird punishment: they are both given a sealed black envelope which they are not allowed to open for an entire week. Haunted by nightmares and day-dreams, Anina in her anxiousness to find out what horrible punishment awaits her, will get mixed up in a series of adventures, involving secret loves, close friendships and dreadful enemies. Without her realizing it, Anina's efforts to understand the content of the envelope turns into a journey to understand the world and her place in it.