As an explaination, I thought I'd mention that I went to a local libary recently that had Doctor Who novels! While the printed adventures of the Doctor hit their heyday during the hiatus, the revived series has also produced its own novels.
When Amy, Rory, and the Doctor land in Appletown, Colorado, nothing seems to be out of the ordinary. But as per usual, appearances are not to be trusted. When Amy and Rory are trapped in the town, the Doctor ends up racing backwards through time in an attempt to save his friends and prevent a bomb that could send Cold War tensions over the edge.
The timey-whimey nature of this novel makes it difficult to follow at time, especially from the Doctor's perspective when the rewind makes him speak backwards. At the same time, it's a nice filler until season seven comes out.
For those who can't find it, a detailed synopsis can be found here