Ice and Sea Mystery

This book is an alternate history, set on April 10, 1912, the day the Titanic set sail. You are an ordinary porter. You originally thought that your job on the Titanic was just to serve a few more guests and carry a few more boxes of goods. However, when you smell the putrid smell in Room D6, the whimpers coming from the room late at night, and the sudden appearance of a body at the last dinner, you understand that there is an uninvited guest on this flight. Or how many?