Barney tries to prove Ted wrong by completing every task on Ted's list of things he thinks the gang is too old to do.
Dr. Reid embarks on his own investigation into the murderr of a young boy years earlier in Las Vegas that he strongly believes has a connection to his own childhood. Jane Lynch ("Two and a Half Men") guest stars as Dr. Reid's mother, Diana Reid.
Frankie intends to find a suitable friend for Brick; Sue sneaks into an R-rated movie with her friend Carly; Axl and his band covertly shoot footage of their biology teacher (Kristin Cavallari) for their music video.
Morris and Banfield are snowed in and trapped at an ER conference in Nebraska. Back in Chicago, Alex and Sarah go behind Sam's back and get into a terrible car accident.
Nick travels to an Italian vineyard to meet with a spy who may know about the death of Nick's father; Letitia confirms to Tripp that she had been unfaithful to him throughout their marriage; Jeremy struggles to keep his affair a secret.