Another spirit haunts The Muppet Christmas Carol: that of Brian Henson's father and Muppets creator, Jim Henson, who died just two years earlier. While the Muppets' fourth feature film is brimming with wit, sharp humor and memorable musical numbers, a palpable sense of sadness hangs heavy over the production. It permeates every scene, every reflection on death and regret, every puppeteer's work, even the way Kermit's head droops or his smile fades seems to whisper "we are not what we once were." And yet Jim Henson's legacy is alive and well in The Muppet Christmas Carol. Brian Henson, his puppeteers and the Muppets themselves refuse to let a day pass wasted, even in their grief, and allow their sadness to not only invade the production but to inhabit it, enrich it and make it a more sincere, emotionally poignant film. Watching Kermit and Robin as Cratchet and Tiny Tim -- a loving father who devotes every ounce of his strength to his work and his son -- is suddenly utterly heartbreaking and incredibly moving. Seeing Scrooge learn what Jim Henson spent his days teaching -- to live life to its fullest, bringing joy to others whenever possible -- suddenly resonates unlike any "Christmas Carol" adaptation before or since. Realizing Brian Henson is coming into his own, in complete, confident command of his craft -- on his feature film directorial debut no less -- is suddenly wonderfully satisfying. "We are not what we once were" suddenly translates to something else entirely: "This too shall pass. We are exactly what Jim wanted us to be."