It's easy to overlook the 9th Doctor, having only been around for one series and preceding the iconic 10th Doctor, and given the sparsity of material on him it can be difficult to pin down a familiar characterization of him, a unique "voice" that distinguishes him from the rest. The Doctor in The Beast of Babylon still doesn't ring unmistakably "true," but Charlie Higson does manage to etch in some good character quirks, specifically a sort of in-text explanation for Christopher Eccleston's awkward, seemingly forced cheerfulness, repeatedly describing him as grinning, but a grin that's almost a snarl, or a grin that's a little off and a little alien. Every bit of this characterization for this sadly neglected Doctor is precious.
The story itself is necessarily compressed, getting just 50 pages, but the basic premise is pitch-perfect and easily good enough to endure in the mythos: sometimes when stars collapse they form black holes, or white dwarfs, or red dwarfs, or wormholes, and sometimes they form Starmen, godlike creatures with only primitive consciousness who wander across the dimensions obliviously causing havoc where they tread. This is a simple but iconic sci-fi concept (in describing their appearance Higson even gives a little tip in the direction of Lovecraft), and Higson ties it all, in the classic Doctor Who tradition, to human history and lore.
The companion character spins her wheels at her introduction, trying just a little too hard to justify herself as companion material, but she's given some interesting texture to redeem her later in the story.
So far I've read seven or eight of these 50th Anniversary novellas, and this one stands out as contributing pieces that could endure in the wider lore of the show. If Higson ever writes more for the character, I'll look forward to it!