Retrieve My Memory Loss Lover - Épisode 5

Erika is the Second Daughter of one of the largest chaebol families in New York City. She witnessed her sister Emma jumping from a building. When she went to the memorial service, she found a child named Adam. Erika left home for her sister's child, but met Owen on the way. Owen claimed that the child was his. Why did Emma jump? Who are the parents of the child? Erika and Owen knew each other?