Doctor Who: Sting of the Zygons by Stephen Cole.   Martha gets a good deal more to do in this novel when she and The Doctor are transported back to the early days of motoring and 'dinosaurs' in the English countryside. Turns out that the Doctor's seen these sort of metal monsters before, and where they roam, the Zygons follow. A fun period romp.

 

Series: Doctor Who (Ten & Martha)
Read October 2007