The book is standard fare for those know Tom Holt's style of writing. If you're expecting an action-packed rollercoaster of thrilling sequences and gasp-inducing fantasy writing, you won't find it here. It's all about the gags, the awkward conversations and exchanges, and just a smattering of plot twists. Things move along at an excruciating pace, but the characters are so strange and funny, with their own distinct traits and ways of looking at the peculiar business of the company that it's easy - and rewarding - just to amble through the laughs and leave the plot to meander along its way, without getting frustrated.
The central character, Paul, is painted as one of Tom Holt's typical anti-heroes; plain, witless and unlucky, but with just enough charm and good instincts to not make the reader feel totally disconnected from him. After a bizarre job interview, Paul lands himself a position at J. W. Wells and Co., and what appears at first to be a mundane, repetitive office job soon turns out to be a cover for something entirely more unusual and clandestine. Add to that his inexplicable, but somehow unshakeable, attraction to an equally quirky new employee and Paul's problems suddenly spiral out of control.
Holt executes his usual array of clever set pieces and puns with clinical precision, and most of the small oddities that occur during the story have a meaning or explanation offered at some point, whilst also leaving room for an intriguing sequel. The 'Portable Door' of the title is perhaps not used as dramatically as it might have been, and is more of a plot device than something upon which the whole book hinges (if you'll forgive the awful door-pun).
This book should give you a good chortle, even though it's not as inspiring a fantasy tale as it could have been. Nevertheless it's good comic entertainment and definitely worth a read.