In the season four finale, Lisa Vanderpump hosts the biggest party of the year: Katie and Tom Schwartz's engagement. Guests of dishonor Kristen and Stassi stir up trouble, and trash-talking Lala creates a scene. Jax must atone for his crimes first in a criminal court, then in a much-anticipated reunion with Stassi. Tom Sandoval debuts his new song in a live performance at SUR, Scheana confronts Ariana, and Lala gets close to both Kristen and James.