When Ted declines Barney's offer to design the new GNB building, Barney ties to woo him by using all of his best womanizing tactics. Meanwhile, Robin is still not over her relationship with Don and drunk dials him.
Deadly jellyfish are used as a murder weapon, and a mysterious woman from Jesse's past returns.
Frankie Jr. is brought in to help with a gruesome murder case involving a youth hockey league. Frustrated with Hope (recurring guest star SHARON LAWRENCE), Cailin (recurring guest star EMILEE WALLACE) asks to stay with Maura. But Maura quickly learns that living with her younger half-sister requires skills she does not have.
