Book excerpt: On Barsoom, the Princess of Helium is missing, and Irene Adler is the number one suspect. As Adler struggles to maintain her liberty and capture her own quarry, there are now two Martians roaming the dark, puddled streets of London, and Princess Dejah Thoris is not dressed for the weather. An official tie-in to the epic Swords of Sorrow crossover event, written by acclaimed writer Leah Moore (Doctor Who, Sherlock Holmes).