Ian Caldwell

<p>Ian Caldwell, who studied history at Princeton, is best-known for his book <i>The Rule of Four</i>, which he co-authored with his friend and writing partner Dustin Thomason, whom he met in high school. Called "the ultimate puzzle book" by <i>The New York Times</i>, the erudite <i>The Rule of Four</i> is centered around four students attempting to solve a centuries-old mystery embedded in a Renaissance text. It spent 49 weeks on the <i>New York Times</i> bestseller list. Caldwell’s next book <i>The Fifth Gospel</i> was published in 2015.</p>