The second in a brainy sci-fi series about modern AI, “Intelligence Horizon” is a worthy sequel to Intelligent Consent (see my review), in which an AI-designing engineer finds himself dealing with a robot carrying a mind identical to his. As in the first instalment, this time we see a pair of humans wrestle with their own consciences as their robotic skills seem destined for military us, whilst the robot and a new friend struggle to survive against villains on Mars. A quick read enhanced by wry humor, Intelligence Horizon suits its genre well.