Having only watched it last night, I have to say that I'm very much with McGrath on this. I really liked it. Lightweight? Yes. A little silly? Yes. Witty and very enjoyable? Absolubtly

Reading some of the comments on The Guardian website, I am astonished at the vindictive hatred of some of them. These people clearly haven't read 'the canon' After all, there are many stories that don't contain any crime. (A Case Of Identity, The Missing Three-Quarter, A Scandal In Bohemia, The Three Students etc.)

As Will has pointed out, some of the plot devices are also pretty questionable. A snake that can hear, anybody?

I think that Christopher Morley (founder of The Baker Street Irregulars) got it about right:

Even in the less successful stories we remain untroubled by any naiveté of plot; it is the character of the immortal pair that we relish..

And that's how I feel about 'The Sign Of Three'