On this week's The Big Bang Theory, Sheldon makes a plan to work on his navigation system project with Leonard and Howard, as well as giving input on his project with Amy at the same time.
Sheldon prepare himself with a hydration backpack that has two tubes attached: one for him to drink water from and the other one for Lentil soup. He does manage to successfully run back and forth between the labs, working on each project and helping them both make headway.
Later on in the laundry room, Penny runs into Sheldon. She suspects he is getting sick after he sneezes. Sheldon denies it, but Penny reminds him that he is a delicate flower who got a cold after watching Frozen and a nose bleed after watching Up. Sure enough, Sheldon wakes up with a cold.
Sheldon insists he is fine and he makes Amy some toast that he sneezes on. Sheldon says he has to go to work, he is fine. Later on, Amy, Leonard and Penny wake up a sleeping Sheldon on the couch. He is alarmed, not remembering what happened.
After thinking back, Sheldon remembers that he took cold medicine. Apparently, he showed up at the lab acting loopy. He notices that he has no pants on and then notices that his notebook with classified information from the Air Force project is missing. At least they find his pants in the microwave!
Everyone goes crazy looking for the notebook. Raj remembers that Sheldon’s phone can track everywhere he went. He grabs his phone and finds that besides work, he went to a cowboy bar. Sheldon has a faint memory of dancing there with a cowboy hat on.
They show up at the bar and the bartender remembers him. The good news is he has the notebook. The bad news is he told the entire bar about the project. But it’s okay, he made everyone pinky swear not to tell.
When they get back home, Amy helps Sheldon feel better. At his request, she sings "Soft Kitty" not only in English, but in German, Mandarin, and Navajo.
Meanwhile, Bernadette is emotional about going back to work and leaving Halley. She confides in Stuart, but doesn’t want to tell Howard. Howard can tell something is wrong, but doesn’t know what. He thinks it must be something he did. He remembers that he forgot to tell her that her aunt Trixie died 6 years ago so he has been sending her birthday cards from her aunt every year. Maybe that’s it.
Howard confronts Bernadette and she finally confesses. Howard tells her that it was hard for him to go back, too. Bernadette feels that if she stays home she will be giving up everything she has worked for. Howard tells her that whatever she decides will be the right choice and she can always undo it. Luckily, Halley is just a “dumb baby,” so she won’t remember. Since Howard is feeling guilty, he also tells Bernadette he has some news about her aunt Trixie.