Brooke Baumer

Sheldon and Amy try to use math to eliminate wedding planning stress. Koothrappali `breaks up' with Wolowitz after realising he is hurting his confidence.

Furious with Ron for his relationship with Wendy, Tom brings his boss's ex-wife Tammy as a date to a party for the Pawnee PD.

Leslie and Ron become adversaries when a dishonest candy company vies for a concessions contract, while everybody else in the department reluctantly helps Tom move out of his house.

Cristina looks to Meredith for advice as she assesses her future at the hospital. Derek and Amelia work together on a difficult surgery involving conjoined twins. Meanwhile, Jo is spread too thin when she tries to work on several cases at once and Stephanie realizes the truth about Bailey's bubble boy case.

Three years into her new job, Leslie battles a tech company and an old friend for the chance to buy an incredible plot of land near Pawnee.

Ron and Leslie's efforts to secure Jamm's vote on the future of the Newport land are complicated by the arrival of old foe Tammy II.