Consider this more a recommendation than a review. This book deserves to be read by anyone who has ever enjoyed Jack Vance, CA Smith, Thorne Smith, Wodehouse, or M John Harrison's (lighter) Viriconium stories. There is a sufficiently complex and oddball mystery to involve readers, but dialog and setting are the true delights of MAJESTRUM. Hengis Hapthorn is a PI, or discriminator, in a far future earth era based on science and reason, but into which magic (sympathetic association) has begun to assert an influence, as it apparently has in ages past. Hapthorn prides himself on his logic, sometimes justifiably, and is disconcerted that magic's influence has turned his hand-built AI, or integrator, into a living familiar, mostly still able to function in AI mode except when hampered by its newly acquired carnal needs (sleep, food, and a lot of each). In earlier short stories (collected in Nightshade's THE GIST HUNTER), the integrator was Hapthorn's foil, providing most of the humorous dialog. In the novel, this is complicated by the integrator's incarnation and also by a magical incident's separation of Hapthorn's personality into his normal, logical mode, and his intuitive sub-persona. Another delight is seeing Hughes venture offworld and dabble in building truly strange pocket cultures, a la Jack Vance.
Quibble: Without going into detail, Nightshade, please edit more carefully in the future.
I am looking forward to the next two Hapthorn novels, and hoping that there are more in the planning.