The Doctor and Lisette

The TARDIS unexpectedly takes the Doctor where he hasn't been in a while. With River Song, Amy, and Rory at his side, they discover a girl trapped and being held hostage by Daleks. There's something different about this girl, by the name of Lisette. He has to figure out what it is, but does Lisette even know? They're future is at stake unless they work together to find out what Lisette is. Things are tense when jealousy arises among the group.