coup de main - noun
\ˌkü-də-ˈmaⁿ
Definition of coup de main : an attack that achieves complete surprise.

Watch: Twenty One Pilots perform 'Level Of Concern' live on The Tonight Show.

Twenty One Pilots performed new song 'Level Of Concern' live for the first time on The Tonight Show Starring Jimmy Fallon last week, with some help from some friends... and one very special fren... Ned (who was first seen in the 'Chlorine' music video)!

Watch the performance below...