Varindra states at the beginning that it would be impossible to describe the latihan kejiwaan, and he doesn't try. You will not find any information about Bapak before he became the founder of Subud - Varindra first encounters him as an old man. I hesitate to call Bapak a leader; his entire focus seems to be on raising up volunteers who do not seek authority. He says it is a great sin to teach - Subud is an experience and not a belief. Instead, Varindra writes very crisp, digestible articles about his memories of Bapak and the other people he meets in Subud.
The way Varindra describes Bapak displays his wisdom, humility, and also his humor. Some of the funniest articles have to do with people trying to emulate Bapak's style or make themselves appear righteous, before they are politely chastened. It is the kind of thing people do, and watching Subud develop reminds one of the way Christianity probably developed after Jesus was no longer around to guide it. It's also wonderful to see how God guides people into Subud and provides coincidental guidance. Bapak's ability to predict these things makes me believe he was legitimately attuned to something spiritual.
In addition to the Subud Trilogy (A Reporter in Subud, Assignment Subud, A Memoir of Subud), my copy also includes a fourth book called "Fruitful Droppings". This last book was written by Varindra after the death of Muhammad Subuh, referred to as Bapak throughout all the books, and is really only connected to Subud because its author was in Subud. It is interesting for me, as an American, to learn about international relations that have nothing to do with my country, but I did not pick up this book to hear about UNICEF budgets. I respect that Varinda dedicated his life to helping people, and that part comes through clearly in all his writing.