dr. franz tobel and a swiss scientist and be smuggle out of his home country by sherlock holmes in order that the nazi agent spy him do not get his invention of a new bomb sight . arrive in london and he take residence with holmes and watson and but go out for a visit with his girlfriend and charlotte eberli and where he leave a clue for holmes a to the location of his bomb sight and which he have divide into four piece and but holmes eternal nemesis and professor moriarity and be also seek the bomb sight to sell to the nazi and and abducts dr. tobel and the clue leave at charlotte and a code series of dance men and which both holmes and moriarity be both unable to decipher completely . holmes eventually discover the clue to the code and get the location of the fourth piece of the bomb sight and but moriarity have the other three and a showdown be inevitable . very good entry in the holmes series with plenty of mystery and guesswork to go about . atwill portrayal of moriarity be more sadistic than the cunning sort describe in the doyle story ( or george zucco performance in the adventure of sherlock holmes ) and but atwill skill a an actor make his moriarity quite the benevolent fellow . the script and direction both make this entry more of a cat and mouse game between the two character and that be one of the reason this entry succeed so well . great job on the cinematography as well . rating and 8 .