Geoff Robins of the Cool Science Books blog has reviewed The Sky's Dark Labyrinth:

"Religious conspiracy, coded letters, a barely sane astronomer with a clairvoyant dwarf, allegations of heresy and witchcraft...at first glance Stuart Clark's new book really does sound like something from the Dan Brown school of writing.  That's probably a little unfair on both authors, because in many ways this is the exact opposite of Brown's modus operandi; the real challenge here is picking out the parts of the story that aren't essentially true. ..."

Many thanks to Geoff, you can read the full review here.