A nice Christmas romp for Steed and Emma, with an in-joke about Cathy Gale to (kinky) boot. However, the episode isn't quite from the top drawer. The setting is somewhat dull, and the support cast also. The confinement of the action to the single location is constraining. The Dickensian theme is somewhat bolted on and extraneous to the action. And the sinister masked Santa appears only in Steed's dream until his appearance in the final shoot-out, and so no tension or interest has been raised about his real identity (and so no thrill of excitement when he or she is finally unmasked).
But the real sin of the episode is to break the implicit rule of the show that, though the action is highly improbable not to say absurd, the laws of physics remain unbroken. There must be a mundane explanation for the mystery, to keep us out of the twilight zone. But here, actual telepathy and ESP are used to interfere with Steed's mind, and the show has just crossed the line into the supernatural.
But the real sin of the episode is to break the implicit rule of the show that, though the action is highly improbable not to say absurd, the laws of physics remain unbroken. There must be a mundane explanation for the mystery, to keep us out of the twilight zone. But here, actual telepathy and ESP are used to interfere with Steed's mind, and the show has just crossed the line into the supernatural.