Zoo Station by David Downing is set in Berlin in 1939, amid the turmoil of World War II. The protagonist is an American journalist, John Russell, who has lived in Germany for the past fifteen years. He has an ex-wife, a twelve-year-old son (who happens to be a member of the Hitler Youth), and a current girlfriend (who happens to be making quite a splash in the entertainment industry during the Hitler regime). Of course things are beginning to get very ugly for the Jewish people, and Russell is quite concerned for his Jewish friends, the Wiesners. The bulk of the story is Russell's attempts to keep this family from being killed by the Nazis.
The worst of Hitler's planning and scheming is still concentrated in Germany, but Russell is well aware of the dictator's plans for world domination. The story is full of complicated intrigues, but the gist is that Russell finds himself working as kind of a double agent. Primarily, he is doing honest reporting about what he sees happening in Germany: the horrible kindertransport of Jewish children to other countries in an attempt to save them, the barbaric treatment of Jews and others at the Sachsenhausen Concentration Camp and Re-Educational Facility, and the constant harassment of Jews and others in their homes.
Russell is contacted by a long-term acquaintance in Russia, however, and asked to write propaganda articles praising the Nazi regime to the people of Russia. As journalist with integrity, writing lies is not something he thinks he can do. Eventually, he is blackmailed by the Russians into spying for them; he also agrees to spy for the British in exchange for help getting his friends, the Wiesners, safely out of the country. The father, Doctor Wiesner, has been beaten and killed, adding to Russell's sense of urgency to get them out of Germany.
In the midst of all this, Russell partners with an American journalist, Tyler McKinley. McKinley is trying to expose the Nazi plans to euthanize all mentally challenged children. He tells Russell:
“Hitler has never made any secret of his plan to purify the race by sterilizing the mentally handicapped and all the other so-called incurables. And the Nazis are always going on about how much it costs to keep all those people in asylums. They actually use it as an example in one of their school textbooks -- you know, how may people’s cars you could build with what it costs to feed and clothe ten incurables for a year. Put the two things together and you get one easy answer: Kill them. It purifies the race and saves money.”
McKinley's probing eventually gets him killed, but not until he is able to leave Russell with the information and the only real clue about how to get definitive documentation of this nefarious plan--adding even more danger to his already precarious position.
The Zoo Station in Berlin is the point from which nearly all of his his clandestine activities takes place. From here he leaves Germany to meet with his Russian contacts, mysterious items are found in lockers, and later he will send at least some of the Wiesners to safety from here.
The entire spy novel is a series of figurative juggling acts and tightrope-walking by Russell as he does his best to save lives, expose evil, and keep his personal integrity intact. While there is some collateral damage to people he cares for, Russell is relatively successful in all of these endeavors.
Zoo Station is the first of five novels featuring Russell, each one named for a different train station.