This supplement deals with World War 2 on the Eastern Front, that is, the conflict between Germany and the Soviet Union. As the introduction points out, it is less familiar in the west than events in Europe or other parts of the world, due in part to the long Cold War that followed the ending of overt hostilities with former allies becoming enemies eyeing one another balefully through the Iron Curtain.
Chapter 1: Welcome to the Eastern Front sets the scene with a brief introduction to the Achthung! Cthulhu setting, mention of the dual-statted nature of this work with game mechanics provided for both the Call of Cthulhu and Savage Worlds rulesets and a chronology of events running from 1831 (when the founder of the cult Theosophical Society, Helena Petrovna Blavatsky, was born) right through to May 1945, taking in revolution and developments in occultism right along with mainstream history. Plenty of neat little details about notable individuals too.
Next, Chapter 2: Tundra, Taigia and Steppe looks at the dark nature of the conflict, two totalitarian states clashing leaves little room for individual opinion and intolerance and brutality are the order of the day. This section concentrates on Russia, explaining the history and the nature of daily life during the war years. There are notes on major cities, rationing and many other things that affect the population - and anyone else roaming around, of course. What transpired as the Germans advanced is also covered, as well as the Baltic States, Poland and Yugoslavia.
Then Chapter 3: The Soviet War Machine looks at the forces arrayed against the Germans, including organisation and their unique mindset - part based on the Russian character and part imposed by the Communist regime. This is followed by Chapter 5: Heroes of the Soviet Union - nothing to do with the decoration of the same name, this tells you how to generate Russian characters under both rulesets covered, and includes new occupations including vor (Russian organised crime) and military ones such as the cavalry (the Russians continued to use the horse in battle until 1943!). If you are interested in getting your character a medal or two there's a very simplistic chart, it is worth finding out more and relating awards to exploits that you have in your backstory or perform during play!
Characters in order, Chapter 6: Weapons and Gear provides the information that you need to kit him out. (Or her, unlike everyone else, the Russians allowed women to enlist in every aspect of the military.) There is also a new weapon quality: Unreliable, to reflect the often poor quality and dodgy supply chain with which Russian troops had to contend... it would be later on that Mikhail Kalasnikov came up with the simple and durable rifle bearing his name! Chapter 6: Across Land and Sky discusses transportation issues and presents a range of Russian vehicles, including tanks (LOTS of tanks!) and aircraft.
Next, Chapter 7: The Weird and Wonderful turns attention to matters occult, including an establishment by the name of the Brain Institute who, amongst other things, make use of Mi-Go technology in their experiments. There's a heady mix of other organisations, cults, individuals and expeditions to get your teeth into as well, ending with a gazetteer of occult activity - plenty to spawn ideas for adventure here. Chapter 8: Hidden and Forgotten Knowledge follows, mixing genuine Russian occultism with Mythos lore seamlessly.
These are followed by Chapter 9: Beasts and Behemoths - an array of monsters - and Chapter 10: Cogs in the Machine, which contains several notable historical figures and a regular army of NPCs for you to make use of, all dual-statted of course. Finally (just in case all that has gone before hasn't given you enough ideas) Chapter 11 provides some adventure seeds and Chapter 12 presents source material that can help you develop atmosphere as well as provide even more ideas.
An enlightening book that provides plenty of resources if you wish to take your campaign into the frozen lands of Mother Russia!