Something sinister is afoot in the house in the west of Ireland in which Sherlock is staying. There are frightened whisperings among the servants and the house's owners are clearly scared. But who - or what? - has terrified them so much that nobody will speak out? Young Sherlock must bring all his powers of deduction to unravelling his greatest mystery yet. Another fast-paced, brilliantly plotted adventure as teenage Sherlock investigates a new crime and comes up against a fresh crop of sinister, clever criminals.