Doctor Who: 30 NuWho Characters Who Would've Made Fantastic Full-Time Companions
2. Adelaide Brooke
Appeared in: The Waters of Mars.
Described at the time as "the Doctor's cleverest and most strong-minded companion yet", Lindsay Duncan's bravura performance as Captain Adelaide Brooke means she remains just that.
Duncan and David Tennant's dynamic chemistry brings out the best in each other's characters; this is one of Tennant's best performances. Adelaide is your archetypal captain of the first off-world colonists. She's wary of anyone who states "fun" as their intention. She's calmness personified when the roof of the base starts creaking under the weight of the relentless water, and stoic when her crew are, one by one, devastatingly changed by it.
While we love that whole captain-taking-control-of-the-situation stuff, it's Adelaide's "starlight in her soul" side of her that makes her interesting and intrigues us. When she recounts events from The Stolen Earth/Journey's End in the cavernous, echoey ice field area, her voice sounds like an ethereal memory. Combined with Murray Gold's The Fate of Little Adelaide makes this one of many compelling scenes between her and the Doctor.
That cleverest and most strong-minded persona of Adelaide then presented itself in the most devastating fashion when she vehemently took the Time Lord Victorious to task.
Then again - in some parallel universe - Adelaide encounters Peter Capaldi's Rebel Time Lord...