What's the Kennection? #263

Challah, eaten on the Jewish Sabbath, is a special braided type of what food?

What's the standard unit of mass in the common U.S. measurement system—about 14.6 kg, though the name is also used for much lighter items, like bullets and counterfeit coins?

M. Night Shyamalan's upcoming movie Glass is a sequel to what 2016 James McAvoy movie, about multiple personality disorder?

What's the name of Plato's best known work, a dialogue about the philosopher-kings of a utopian society called Kallipolis?

What's the more familiar married name of Emma Knight, Diana Rigg's character on TV's The Avengers?

What's the "Kennection"?