The Vanished Man, by Jeffery Deaver
Fifth in the Lincoln Rhyme series by Jeffery Deaver...
On with the re-reading!
The important bit to remind me of which book this is is that it's the one with the magicians. And of course it's all twisty and confusing, there's even some twisty bits within the story with the characters messing with each other (and therefore the reader) as to what actually happened.
The Rhyme books always have that interesting juxtaposition of incredible mental power with complete physical dependency, but this one has it spelled out a bit more explicitly than most.