Barney uses his best womanizing tactics to try to convince Ted to design the new GNB building; Robin drunk dials Don.

Jeff falls into old habits after reconnecting with Alan (Rob Corddry), a former law firm colleague; Abed, Annie and Troy look for dirt on Alan.

Gloria decides to honor her late grandmother by cooking more traditional Colombian meals; Claire finds out Alex is interested in a boy; Mitchell’s aversion to public displays of affection causes an argument.

Alicia makes her decision about whether to stay with Peter or pursue a relationship with Will.

When Barney convinces the gang to help his mom move out of her home, they quickly learn that she has been very protective of Barney and lied to him about events throughout his life. Meanwhile, Ted gets upset when Robin oversells him to a blind date.

As the new semester begins, the study group gathers to tackle Anthropology 101; Jeff struggles to establish decorum with Britta and Annie; Señor Chang decides to enroll as a student so he can join the study group.

Phil finally agrees to sell the old station wagon but only after a family trip down memory lane; Cameron asks Jay for help when Mitchell decides to build a life-size princess castle for Lily.

The team tries to track down their rogue member, and discover the artifact they have is unexpectedly powerful. Meanwhile, Claudia wonders about her future with the Warehouse team and Pete must choose between Kelly and the mission.

Dr. Grant attempts to return to 1947 but when Carter intrudes, they both wind up stuck in the past under the threat of altering present-day Eureka once again.

Pete and Myka use H.G. Wells’s time machine to travel back to 1961.