Future Ted tells the kids how they had found doppelgangers for everyone in the gang except for Barney. Lily says they will start trying to have kids when they see his doppelganger and it's not long before they actually see him -- Taxi driver Barney.
Lily tells Marshall they can't tell anyone they're trying for a baby because it will be like inviting their friends into the bedroom. We then see everyone invading Marshall and Lily's privacy as they try to have sex. Lily shows Robin the photo of Barney and she is impressed.
Everyone convinces Ted to go blonde by telling him not to do it. Meanwhile, things with Robin and Don are going well.
Marshall thanks the brunette cab driver who turns out to be Barney. Barney tells him that he was listening to a recording of him, not him. He tells Marshall that he has been trying to get with women from around the world. Marshall goes to tell Lily the truth and then they get intimate instead.
Robin tells Ted that she got a job offer -- in Chicago. Ted says that she has been following her jobs around and not considering relationships better. Robin tells everyone about the job offer and then tells them that she is taking it. She doesn't end up taking the job, however. Don tells Robin that he got offered the job in Chicago and took it.
Marshall and Lily see another Barney doppelganger and it turns out to be Barney again. They realize that it means he wants them to have children.
Robin goes to Ted and they talk about how things have changed over five years. Ted says that we eventually become our own doppelgangers -- they look like us but are really different. She nearly kisses him but then looks at his hair and laughs.