'When you have eliminated the impossible, whatever remains, however improbable, must be the truth.' So said Sherlock Holmes. You may not be a detective, but you are on the trail of a mystery - if you keep on asking the right questions, you'll get answers that make proper sense. You face a perplexing dilemma. There's no obvious easy way to solve a problem. But if you keep your wits about you, you'll see a brilliant way to proceed. The impossible is... impossible. But the improbable? That's more feasible than you think!