While pursuing a dangerous arms dealer, the team is shocked when Bishop is implicated in an old NSA leak while Gibbs and Marcie realize the killer they've been tracking may be onto them.

Barry and Iris come together to try and stop a dangerous force from destroying Central City.

Jimmy asks The Roots to improvise songs about audience members in a brand-new Freestylin’ with The Roots, then chats with Kevin Hart and Chrissy Metz before welcoming musical guest St. Vincent.

Host Carson Daly reveals who America has chosen to be the winner. Special performances by chart-topping artists and finalist/coach duets with Kelly Clarkson, Nick Jonas, John Legend, and Blake Shelton.

The family gathers for Kevin and Madison's wedding.