Welcome to the 21st installment "Rider's Digest," a feature devoted to what people are reading on the CTA. Please post what you read this week on the CTA in comments. Rebecca Perlow, 28, of Alsip who describes herself as a bibliophile, sometime freelancer and full-time art hag, has been keeping track of what people are reading on the CTA on a weekly basis. Follow her on Twitter @trickstertara. Below is her 21st dispatch. Photos are courtesy of Amazon.