Likely the first, and certainly one of only a few, film references to Sherlock Holmes' cocaine injecting, as described in the original stories. Even though cocaine and opium had only recently became illegal, there was nonetheless a rising tide of moral opposition against them at the time of this film (just six months later, in Chaplin's Easy Street, the self-injector is portrayed as a depraved degenerate) - which makes this film's light-hearted depiction all the more surprising. And while busy coking up, Holmes is tracking down smugglers of that evil menance - opium (which used to be known as “hop”, the name providing the source for the film's puns, gags, and title). Fifteen years later, Alma Rubens died at just 33 - after a long battle with addiction. A film that's somewhat funny, quite silly, and totally bizarre (after all, it's a Tod Browning joint), reportedly “Everybody's Hero” Fairbanks hated it (after all, it has none of his heroics or acrobatics). That's a good enough reason to wholeheartedly embrace it.