Sin ser una de las mejores novela de Holmes/ Doyle, es sin duda una obra que se lee con cierto interés y simpatía. Por desgracia es demasiado similar a ciertas partes de Estudio en Escarlata -los mormones se cambian por los masones- y el misterio, si uno conoce las obras de Doyle sobre el fantástico detective, salta a la vista a mitad de libro. No obstante, reúne los suficientes elementos para pasar unas horas entretenidas con su lectura: el retrato de los malvados masones, el ambiente del pueblo, el rocambolesco asesinato de Mr. Douglas... ( )

Book of the Month Club

Essentially, this one is 'A Study in Scarlet' with Masons instead of Mormons. I would, indeed, go so far as to say that it's much worse than 'A Study in Scarlet'.
My logic: I read Sherlock Holmes books to read about Sherlock Holmes solving cases. This book was written, however, to be an 'adventure in America.' It's got the kind of off-the-wall sensationalism that would have attracted the British reading audience at that time. The mystery isn't terrible, but most of the book isn't the mystery. Most of the book is either set in the America storyline or is not actually involved in Holmes' solution to the case.
Because this is just a rehash of a plot which Doyle had already executed-- and executed better-- I would say that the only reason anyone should hunt down and read this particular story is for the glory of having read them all. It's not painful to read, nor is it truly disappointing, but it's not interesting.
This story is, however, interesting for the similarities it has to that final propaganda story, 'His Last Bow.' Both the main character in the second half of 'The Valley of Fear' and Holmes in 'His Last Bow' perform eerily similar feats of deception. However, I would classify both of these stories as severely sub-par Conan Doyle. ( )

Another of the great Sherlock Holmes murder mystery novels with an American backdrop based around members of a crooked organisation trying to kill the Pinkerton's detective who broke up their gang. ( )

Both halves were good, but they didn't flow well together. ( )