translation.en: Here he kept his wife imprisoned in her room while he, disguised in a beard, followed Dr. Mortimer to Baker Street and afterwards to the station and to the Northumberland Hotel. His wife had some inkling of his plans; but she had such a fear of her husband--a fear founded upon brutal ill-treatment--that she dare not write to warn the man whom she knew to be in danger.
translation.pl: Stapleton zamykał żonę na klucz a sam, przyprawiwszy brodę, dla niepoznaki, śledził każdy krok doktora Mortimer, jeździł za nim na Baker-Street, a następnie na dworzec i do hotelu Northumberland.