I adore this episode, and it's one of my favorite episodes of Doctor Who ever. It introduces one of my favorite characters of all time in anything ever in Donna, and it's just so silly.

Ten is mopey and sad and wet and pathetic and it's incredibly funny and touching to see someone like Donna (self-absorbed, forceful, and very keen on being a nuisance, but ultimately a good person with a big heart) break through the shell of his grief a little bit and unintentionally save him from himself.

Catherine Tate and David Tennant have fantastic chemistry and it's always so nice to go back and rewatch this knowing that that's why we ended up getting a full season of Donna as a companion. They just bounce off of each other so well and it's delightful.