Sheldon gets his dream summer job at the local train museum. Also, George and Missy bond when Missy embarks on a new stage of womanhood, and Georgie discovers Mary’s guilty pleasure.
Christy is certain that Bonnie is in over her head when she invites a freshly paroled Tammy to stay with them.
The FBI's assistant director of national security joins the BAU as it investigates the quadruple homicide of a group of roommates in St. Louis.
After Tim has a heart attack, he becomes clingy and annoys the entire family; Greg and Jen make a pact to keep their baby's gender a secret; Sophia's new pet frog turns out to be a dangerous species; Matt and Colleen get news about their adoption.