The author concentrates on various topics concerning the problem of faithfulness in translation of historical sources and the errors resulting from the over- and misinterpretations of the text. He states that the translation is always an interpretation. Sometimes a small change in the translation, that is the interpretation of the text of the source, may cause a serious error. The dangers and pitfalls of translation arise not only due to the ambiguity of the language of the source and the use of alternative terms, which meanings differ from each other very subtle. Cetwinski emphasizes, that the translator is obliged to take into consideration the whole historical and cultural context of the text as well as to decipher and properly interpret intentions and motives of its author. As long as the translator does not know the context, he is unable to understand the text, especially when the author alludes to something or uses irony. He has to know, who wrote the text and who was its addressee. Unless he knows it, he is unable to understand the form and the content of the source, he is translating. The translator should also understand the subtleties of metaphors and symbols used by the author as well as philosophical, theological or 'scientific' concepts, etc. The Book of Henryków was addressed to successive generations of Cistercians (and not medievalists). Cetwinski points out exact examples of erroneous translations of its fragments, which resulted from misunderstanding of the text. Its translators perceived it as a simple reflection of the surrounding world and not as a complex historical fact. Cetwinski's approach makes it evident, that the Book of Henryków was not only a register of Cistercians' assets. It may be read, as other medieval texts, not only as a literal story that includes various events that occurred in the neighborhood of the monastery. The Book of Henryków had its metaphoric, moral and mystical layers. If the translator wants to understand them, he must be meticulous, astute and insightful. After all, the Book of Henryków was kept not only for educational purposes, but also as an amusement.