Isaac Asimov’s Robot City: Robots and Aliens: Intruder
This is the third book in the second Asimov tie in series. Its one of the better ones of the nine I have read so far, and I actually enjoyed reading it (some of the others felt like a bit of a chore). This one covers a return to Robot City, where an outside force has disrupted the operation of the city for its own nefarious purposes.