The aliens possess a language that, when understood, allows the speaker to transcend time. As soon as she starts to learn their language she has vague, strange flashbacks, and only as she learns more and more does it finally become clear that they're actually flash-forwards, that her understanding of their language has given her the same ability they possess -- she can influence the future by seeing it in person and changing it in the present in order to achieve what she's seeing in the future. It's trippy and beautifully shot and edited, and the way the story progresses from a simple sci-fi narrative into a meta-style circular tale was really well done.

IMO

Tim