This is surely one of the better Eighth Doctor Adventures, in a series that I was somewhat losing confidence in a few volumes back; by odd coincidence, it is set in 2012. We start off with a good chunk of the novel exploring what's happened to the Brigadier recently (last seen, from his own point of view anyway, in the very first Eighth Doctor novel, The Dying Days) and the peculiar dimensional opening between present day England and the magical parallel world of Avalon, where humans and the reptiles sometimes known as Silurians struggle for mastery of the land, and the British Army and two meddling Time Lords get caught up in the local power politics. The opening section is absolutely gripping; it settles down a bit as it goes on, but never lost my attention. The book also brings up the concept of a person becoming a Tardis, and vice versa, which is of course picked up and developed by Neil Gaiman in The Doctor's Wife.

Depending on how one counts Minuet in Hell (and I'd rather not), this is actually the last appearance of the Brigadier in the Doctor's personal timeline, though he remains a constant point of reference and appears in several spinoff stories (including an SJA episode) right up until his departure is reported on-screen in last year's series. It's a good way for the character to bow out.