The book of the Russian philologist-Germanist E.R. Squires introduces various aspects of scientific work that will be interesting not only for scientific colleagues, but will be able to captivate every inquisitive reader. Classes with unexplored German manuscripts of the Middle Ages and early modern times and old printed publications located in libraries and archives of Russia often posed difficult tasks for the researcher. The book contains truly detective stories from three decades of her scientific work, in which unexpected decisions and even discoveries were achieved by various methods that philological science has - unfairly, as the author shows, considered inaccurate.