Kat's mental health crisis reaches a breaking point, triggering widespread damage. Mandy has an emergency, and Serena slips into loneliness.

Kat's episode brings destructive fallout for Marcus and Justin. Carol and Mitch contemplate a big step, and Serena exposes a secret about Kat's fall.

Kat and Justin's romance and Olympic dreams teeter on an edge while the relationships around them skid toward their own crossroads.