Ten years ago, Sabalom Glitz's gang stole an item which the owners have decided they want back. By blackmail and coercion, the Doctor and his companion - shape-shifting penguin Frobisher - are forced to join Glitz and Dibber in tracking down Glitz's old partners to assist in this repossession.

For both Glitz and the Doctor, the story is explicity placed between seasons 23 and 24, with additional frequent references to other stories. It seems that the BBC novels must either be direct sequels to television shows, or - like Mission: Impractical - have roots in earlier novels which must render them rather impenetrable for the selective reader. In this case, the main alien characters will be familiar to followers of David's work.

There's more than a hint of The Blues Brothers about the recruitment of Glitz's gang, which seems to take forever without much happening. However, David now seems to be consistently avoiding excess detail, and so the pace is reasonable. There remains a tendency to over-emphasise simple points and neither comedy nor sentiment seem compatible with his style. Also, a couple of the plot twists are easily guessable, but that doesn't detract. A whiff of gimmick lingers in the use of Frobisher. I was expecting an overload of whimsy, but thankfully he's treated seriously and I wouldn't be averse to a reappearance.

The references to non-Doctor Who fictional sources are, as usual, irritating. Definitely homage rather than plagiarism, they remain a distraction - it's difficult to submerge onesself in a story if the author frequently interrupts himself to demonstrate his eclectic taste. A brief appearance by James Bond can only lead to the suspicion that the author is not even aspiring to originality any more. Once more it is difficult to avoid concluding that if more time and effort were spent on tidying up occasionally clumsy phrasing, and on clarifying motivations, David's books could be so much better. His own characters are fine, so why such an apparent lack of confidence in them?

Again this is his best book to date, but ultimately the potential is diluted by this lack of focus. There's a perfectly good story here, whimpering just below the surface. He's still improving, but yet more discipline is required. And what's so impractical about it, anyway?