Leppin's "Blaugast" and "Severin's Journey into the dark" are the best books to accompany a journey to Prague. Both feature seedy, dubious characters wandering around the old town at the beginning of the 20th century. The books are thoroughly depraved, but very good indeed.
Best places to buy this book are Palac Knih on Vaclavske Nam (the English language section is downstairs) and Shakespeare and Sons on Krymska.
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