Season 8, Episode 1 - The Locomotion Interruption
Aired September 22, 2014
After spending forty-five days riding the rails, Sheldon's cross-country journey comes to an end in Arizona when he is robbed on a sleeper train. In need of assistance, Leonard and Amy must drive out to Arizona to pick him up.
Meanwhile, Bernadette helps Penny get a job interview at her pharmaceutical company, and Howard is freaked out by how close Stuart and Mrs. Wolowitz have become.
Season 10, Episode 15 - The Locomotion Reverberation
Aired February 9, 2017
When Sheldon proves to be a distraction to Leonard and Howard as they work on the military project, they find a way to keep him occupied but his absence threatens to derail the project after Colonel Williams demands the gyroscope be made smaller.
Meanwhile, Penny and Amy take Bernadette on her first girls' night out since Halley was born, leaving Raj and Stuart to look after the baby.