To dispense with the mystery: it was fine. Hercule was in fine fettle, and Hastings was his usual dim sidekick.
But the talking dog? Whaaaaat?
Thank FSM that she never used this plot device again (please tell me she never used this plot device again). Because it did not work at all, and was weird and stupid. Not clever, not funny.
I don't know if it quite reaches the standard of awfulness set by The Big Four, but it was pretty bad.