Taylor Swift recently released a song for the Hunger Games movie soundtrack and after a long period of waiting, they released an official video for it too. Here is my interpretation of it:

At the beginning, inside a small, house with a melancholy atmosphere, 2 people are sitting in a room with a fire going. There is a man and a woman. The man has long brown hair, and I presume that he is supposed to be an older version of Peeta. The woman has dark brunette hair, and like Katniss, blue-gray eyes. I think that it is her and they are sitting together with Peeta playing the guitar. It then shows Taylor Swift, dressed all in white, walking through the woods. At first we don't know where she is, but then it shows nightlock berries and we realize she is walking around the previously abandoned arena. It transitions frequently between this and Katniss and Peeta in the house. At the point where she says "Darling, everything's on fire.", the wide hills in the background seemed to be engulfed in flames, so perhaps she is reliving the past. We do not know who she is supposed to be until we see that she is walking through a graveyard. At the moment she lied down on a crumpled gravestone, I realized that she was Prim. She keeps walking until she sees a deer on the other side of a small lake. He vanishes into thin air and at that moment we can tell that she as well as the other animals around her are ghosts, which would make sense because she died in the last book. After that, she is someone where else. In the ruins of an old town, she goes into a broke down house and finds the mockinjgay pin rusty and covered with ash in an old drawer. I believe that this means that she is revisiting her old house in district 12. Soon after that it ends, with older Katniss and Peeta again and leaves you wondering. Basically I think that the ghost of Primrose is walking around the arena and district 12 to bring her memories of why she died and of Katniss and her family. The grave that she sits on is hers and the deer vanishing was to show us that she was a ghost. The song that she sings can be interpreted to what Katniss said to her, before she left, and how she felt during the games. Katniss and Peeta are singing it as well, probably for the same reason but unaware that Prim's ghost can hear them and is singing along. Taylor Swift did a great job on the video and I hoped you liked reading this.