i love this episode . it one of my favorite . here we see david tennant for the first time a the tenth doctor ( exclude the thirty second at the end of the parting of the way ) . and he be brilliant . he be totally natural . the rest of the cast be very good a well . billie piper be also very natural a the doctor companion . the script be good and with some brilliant line ( see quote page ) . the pas of the episode be good and with a good lot of action ( the crash landing tardis and the attack of the father christmas and the christmas tree and the sword fight . ) but not too much and and there be no excessive violence . in fact there be practically no violence and in less you include the sword fight and and even there everything be keep proper represent no blood . we also hear what i think be be the first reference to torchwood . the episode keep up until the very end to sum it up and i say go and watch this episode as soon a you can .