Doctor Who: Alien Bodies (Eighth Doctor Adventures, #6)
by Lawrence Miles
Extremely fun, in a giddy way. The mystery is excellent, and the solution is even better. The quiet moments in the prologue and epilogue are also lovely. I totally loved the Doctor in this, and the book is full of very Douglas Adams descriptions, especially this:
"Every now and then, Sam found herself thinking of the Doctor as a set of responses, not a man---half-man---person at all.... A function of the universe, whose purpose was to (a) break into places and (b) break out of them again."