Clues give both a warning/promise and a hint of the location of the next clue
 
Clue #1 leads to Clue #2 Is given to some random passengers. Leads behind the Clock on the Grand Staircase, (warns about how times wears all things to dust?).
Clue #2 Leads to Clue # 3 at the murder scene or wealthy female passenger. Is written in blood on the wall (Promises path to eternal life?)
Clue #3 Leads to Clue #4 engraved on Neutronium Diamond ring. Most expensive gem on the ship. Located in Purser's safe. (maybe owned by murdered passenger?)(Warns about the perils of greed?)
Clue #5 Leads to Clue#6 Ship's library inside ancient Atlantean (Syrne) book of Necromancy that does not belong on the ship. (Promises power beyond wealth?)
Clue #6 is a confusing and disturbing riddle that has hardly any meaning but hints at the true solution which is to find out of place marked letters in the previous clues (including #6) to find the name of a passenger who is not present on the ship but has cargo stored on the vessel. This cargo (supposedly) is the Shard.