According to The Straits Times of Singapore: 'Exit Mr. Brent' is a different type of yarn. We have met Mr. Brent twice before. He is the megalomaniac scientist and surgeon, with a stronghold on a hidden island in the Atlantic, and his specialty is a brain operation that turns his victims into automata, completely under his power. He also dabbles in international politics and his ambition is to set the whole world by the ears. Although 'Exit Mr. Brent' has a very complicated plot, it is full of excitement and intrigue and Brent and his two enemies, Detectives Royston and Castle, fight the battle of wits ardently and with varying fortune until the end, when a final stop is put to Brent's machinations".