The of Blackmail relies on traditional intertitles (text cards shown between scenes) to convey dialogue and plot information.
: Given that "Blackmail" is a classic, silent film transitioned to sound (it started as a silent film but was reworked with sound), finding modern subtitles might be challenging but not impossible. There are several archives and film restoration projects dedicated to classic cinema that might offer subtitled versions. blackmail 1929 subtitles