“…for I felt suddenly as though I were talking to a child…”  pg. 188

“I’ve got my wife locked up in there,” explained Wilson calmly.  “She’s going to stay there till the day after tomorrow and then we’re going to move away.”  Pg.143

Here, Wilson is telling Michaelis all about how he’s going to take Myrtle and move her away.  He had found out that she was having an affair, and decided to remove her from the situation and to place her somewhere else, amongst a new environment.  Here, he’s also acting like a parent by disciplining Myrtle’s actions by sending her to her room, and then grounding her permanently.  He's grounding her permanently by taking her away from the situation, and thus running away.