The Devil in the White City pg. 288-320

Although Holmes has kept Minnie and her sister Anna alive for quite some time now, their lives are beginning to look towards the end. Holmes has convinced Anna that she is very talented and should study art in Europe. So Anna writes to her family in Texas explaining that her, Minnie, and Holmes will be going to Milwaukee, then Maine, the New York then sail to Germany, England, and France. Holmes says that her parents won't need to worry about the girls because he will take care of them financially.

Before leaving for Milwaukee the next day, Minnie prepares the flat for the next tenants as Holmes takes Anna to see his World's Fair Hotel. He asks Anna if she would mind going into the walk-in vault to retrieve a document he had left inside. Of course she cheerfully complies. Little does she know Holmes is going to shut her in the vault and release a deadly gas. Anna is embarrassed as she believes that she accidentally shut the door. She begins pounding on the door with her heel waiting for Holmes to let her out. After a couple of minutes with no answer from Holmes she believes that he has gone elsewhere in the building or left to check on the shops below.

Just outside the vault Holmes was pondering his three options: He could, in the last few seconds, "rush to the door, throw it open, hold her in his arms, and weep with her at the tragedy just barely averted; he could "open the door and look in on Anna and give her a big smile--just to let her know that this was no accident--then close the door again, slam it, and return to his chair to see what might happen next"; or, he could "flood the vault, right now, with gas." Holmes, a fiend of instant gratification, of course, chose to flood the vault with gas.

Two days later, Holmes called upon Cephas Humphrey to pick up a box (about the dimensions of a coffin) and a trunk (Anna's belongings). Later evidence suggests that he drove the trunk to the home of Charles Chappell, the man who had converted Holmes's past two ladies into skeletons. As for the rectangular, wooden box, Holmes gave Pitezel's wife, Carrie, a collection of dresses, shoes, and hats that had belonged to "his cousin Minnie Williams." Holmes suggested that Carrie cut up the dresses and use the material to make clothing for her three daughters.

Holmes soon moved on and proposed to Georgiana Yoke, a young blond from Franklin, Indiana. He did warn her that for the marriage he would have to use his dead uncle's name Henry Mansfield Howard.