Kourtney flies to Los Angeles to have it out with sister Kim, who is planning to "borrow"—without permission—Kourtney's house for North's birthday bash. Meanwhile, too much partying in the Hamptons lands Scott in the hospital, and to the realization that things need to change.

Kourtney and Scott try to avoid repeating their past mistakes after he unexpectedly checks out of rehab; at the same time, Kim begins to doubt how loyal her best friend Jonathan really is after family secrets are leaked to the media.