Marshall and Lily go to Atlantic city to elope, but are held up by the three-day wait for a license.
The gang struggles to quit smoking; Robin clashes with a new, jaded co-worker.
At Marshall and Lily's wedding, Barney discovers that Ted and Robin have a secret that they have been hiding for weeks.
Marshall and Lily try to figure out how to conceive a baby with the gender of their choice; Robin's perky new co-anchor irritates her.
When Zoey enrolls in Ted's class, she tries to convince his students to help save the building from being torn down for his project; Marshall and Lily notice Robin marching in the Halloween parade of shame.