translation.en: Another item had been added to that constant and apparently purposeless series of small mysteries which had succeeded each other so rapidly. Setting aside the whole grim story of Sir Charles's death, we had a line of inexplicable incidents all within the limits of two days, which included the receipt of the printed letter, the black-bearded spy in the hansom, the loss of the new brown boot, the loss of the old black boot, and now the return of the new brown boot.
translation.pl: Nie licząc już śmierci sir Karola, w ciągu dwóch dni wpadaliśmy z jednego zdziwienia w drugie, łamiąc sobie głowę: to nad drukowanym listem, to nad zjawieniem się szpiegów, nad zniknięciem żółtego, to czarnego buta. Odnalezienie żółtego było nowym sękiem.