Marshall tries to prove that his attractive female colleague (Amanda Peet) kissed him; Robin discovers that a drinking game has been made up about her.
Marshall becomes obsessed with saving the environment after seeing a documentary on garbage; Ted runs into The Captain; Barney admits he has feelings for a woman.
Marshall quits his job at Goliath National Bank to volunteer at an environmental organization; Ted and Zooey continue to butt heads over the future of the Arcadia.
A famous comic-book artist (guest star Frankie Muniz) helps to search for a serial killer in Los Angeles.
When Ted loses his job, he decides to start his own architectural firm.