As construction begins in Spain on Sam's dream rollercoaster, Allie decides she cannot continue their affair. At home Sam's wife Charlotte cannot understand his black mood but soon learns the truth.

Charlotte and Sam struggle to save their marriage, but when they eventually separate, Sam returns to Allie.

The Dragon Khan roller coaster nears completion just as Allie's baby makes an early appearance. Sam is now "having his cake", shared by Charlotte and Allie, but can this situation last?