This is probably the best of the Dr Who novels to feature Donna. Her character is captured brilliantly and you can hear Catherine T saying the lines. Highlight has to be the Pythonesque/Hitchikery section in the middle of the book where Donna is mistaken for The Ginger Goddess. Laugh out loud funny. And the overall story`s good one too, concerning the usual notions of artificial intelligence/conscience but in a fresh & entertaining way. Buy it!