New Who Countdown: Number 5

"Human Nature"/"Family of Blood"
Series: 3
Doctor: David Tennant
Companion: Martha Jones (Freema Agyeman)
Writer: Paul Cornell

Martha and the Doctor are in dire trouble as a ruthless, formless alien family (the aptly named Family of Blood) with their army of scarecrows comes to terrorize a boys military school where the Doctor, believing he is human and forgetting all about his Time Lordiness, has escaped to.  Not only do the episodes beg the question, "What happens to the world if the Doctor forgets who he is, even if intentional?" but it also goes further than many Doctor Who episodes by acknowledging race, gender, and class differences.

This story shows Martha at her most tolerable.  When she's not pining for the Doctor, she is very clever, resilient, resourceful, and brave, and as the glue holding the Doctor together in this story, she finally gets the writing and character she deserves.  She has a mostly okay personality in series three, but these are the episodes when she shines - it's up to her, not the Doctor, to save the day.  While the Doctor is away, and John Smith is at play, Martha becomes the heroine we always knew she could be after seeing her first kick butt in "Smith & Jones".  Unlike Rose, who we all loved for her heart, naivety, and youth, Martha is a match in wit for anyone, even the Doctor.

The guest stars in this two parter are fantastic as well.  We know two of them as Game of Thrones actors now (Harry Lloyd and Thomas Sangster), but this is before, and they are both still wonderful.  And Jessica Hynes (nee Stevenson) who made us hate her and love her as the nurse at the school whom John Smith falls in love with.

But the real gem of this two parter is David Tennant.  It is admittedly hard for a Whovian as myself to watch the Doctor be anything but his regular amazing self, but David Tennant plays the part of John Smith with so much humility, curiosity, wonder, and sadness that it actually persuaded me that he could be amazing in anything, as anyone.  (I was mistaken later in life, and came to the realization that much of it depends on a good script, but that's not the point.) Because of his brilliance (and, of course, the writing of Paul Cornell), one of David Tennant's best moments in Doctor Who comes not as the Time Lord Doctor, but as a simple human high school history teacher.