Sherlock Holmes's great-great-great-grandkids use modern technology to crack his unsolved cases—like the mystery of a vanished painting—in this series debut. "A fast-paced, entertaining mystery." — Booklist Xena and Xander Holmes think living in London will be boring. But one afternoon, they're handed a cryptic note that leads them to a hidden room—and a secret society. When they discover they're related to Sherlock Holmes and inherit his unsolved casebook, life becomes so much more exciting. The siblings set out to solve the cases their famous ancestor couldn't, starting with the mystery of a prized painting that vanished more than a hundred years ago. Can two smart twenty-first-century kids succeed where Sherlock Holmes could not? "Barrett presents readers with great characters and a believable mystery solved credibly. . . . A strong start to what will undoubtedly remain an enjoyable series." — Kirkus Reviews