What is the main conflict in Running Out of Time by Margaret Peterson Haddix?

Running Out Of Time by Margaret Peterson Haddix is a thriller for young adults. Jessie Keyser and other children her age believe she is living in Clifton, Indiana in 1840. A diphtheria epidemic attacks the children of Clifton and Jessie's mother is forced to reveal that the year is actually 1996. Jessie must go to the outside world to find help from a mysterious man named Mr. Neely. Ultimately, Jessie figures out a way to tell the world about Clifton and save her sick friends.