The three games on the first volume are "The Mummy's Curse", "The Case of the Mystified Murderess" and "The Case of the Tin Soldier". Each one is fairly complex but solvable - all the clues are there, if only you are observant enough to pick out the important ones from the red herrings! It is important to peruse The London Times around the period of the crime as there was always some small but essential clue to be found there. Other sources such as the Baker Street Irregulars can be less useful, but can still produce hints from time to time. Holmes' regular sources such as Shinwell and Pike are only helpful when the crime intersects with their sphere of influence, so it was important to consider whether they would be able to help before visiting them. It is also imperative to take notes as you progress to avoid losing track of names, dates and places.