Sherlock Holmes has received a visit from the widow Gracie, the wife of the late Archibald Gracie IV - a Titanic survivor. Conspiracies are rife and she needs to know the truth: Why did Titanic really sink? At the age of 67 years, Holmes is happy to oblige, now out of retirement, and with his dear friend Dr. Watson at his side, this is his first ever cold case review.