It's campaigns like these that, despite the best of intentions, have earned Russell his reputation as a purveyor of the highest order of fanwank.
That said, however, despite myriad failings, Instruments of Darkness is a reasonable sequel to Business Unusual.
Irritations include a marginalised and relatively-poorly-characterised Doctor, reliance on continuity (although it's much better than some of the author's previous work), stylistic inconsistencies, dialogue peeled straight from the Star Wars prequels and Russell indulging his Bond fetish. Naming a pair of female assassins Ms de Menour and Ms (Mal) Feasance? Inserting a piece about the Doctor introducing Fleming to the ornithologist on whom Bond was based? The cult-series mix is simply too much for an admittedly-pulpy premise to bear.
But in spite of these elements, Russell deftly portrays a series of interconnected characters whose reliance upon each other is notable. Throughout the text, couplets emerge where each member is completely dependent on the other - for existence, validation, love. Even the Doctor is not immune as he encounters the companion that wasn't, Evelyn Smythe; and in fact only Mel appears immune.
This symbiosis is woven unobtrusively throughout and only it hits the reader with real force when it becomes apparent at the novel's conclusion. It's sweetly juxtaposed with the climactic fireworks brought about by some old-school Doctor trickery reminiscent of Pyramids of Mars.
In two words: Mixed bag.