Reinhard Heydrich assassination, Prague, Czech Resistance exhibit, Boromejsky Orthodox Church
Readers of Petr's Diary, who do not have a firm grounding in WWII history, may be misled by the reporter-type detached entries of Petr Ginz. His listing of the Occupation events can be bland.
For a more gut-level start in understanding what life was like and how it evolved under the Nazi regime and aided by Czech protectionists, look into this event as an example, and go deeper.
Find Operation Anthropoid, leading to the assassination of a high-ranking Nazi official, Reinhard Heydrich. He ordered the methodical deportation and death of tens of thousands of Jews, Gypsies, and others. See Gypsies, Roma - Holocaust. See a detailed chronology of the German occupation in Prague and the surrounding area, and photos, see http://www.army.cz/images/id_7001_8000/7419/assassination-en.pdf. "Assassination" refers to Operation Anthropoid, and includes events in the years preceding, and the reprisals afterwards, especially in Lidice, the town that was decimated.
This is an exhibit in the Boromejsky Orthodox Church (Orthodox Catholic, not Roman Catholic), also known as the Orthodox Church of Saints Cyril and Methodius (www.radio.cz/en/article/85056) where some of the partisans had been hidden by the priest. Then one of the partisans who had participated, but escaped, revealed their location to the Nazis apparently in hopes of saving his family from retribution, and the others were trapped there.
These events were scripted into a film in the 1970's, "Operation Daybreak," available on the internet. The copies are poor in audio - feel free to return for a better. There may be foreign language subtitles. Worth a remake, Hollywood.