Butler- Sonix Grenades

  Artemis knew it too. It was most of the verbal detonation code for the fairy sonix grenade magnetized to the underside of the table. One of Butler’s little security devices. All they needed was one more word and the grenade would explode, sending a solid wall of sound charging through the building, blowing out every window and eardrum. There would be no smoke or flame, but anyone within a ten meter radius not wearing earplugs had about five seconds before severe pain set in. One more word.
...
  The old lady scratched her head with the revolver’s barrel. “Richard of York? I remember now, the nuns taught us that in school. Richard of York gave battle in vain. It’s one of those memory tricks. The colors of the rainbow.”

  Rainbow. The final word. Artemis remembered, just in time, to slacken his jaw. If his teeth were clenched, the sonic waves would shatter them like sugar glass.

  The grenade detonated in a blast of compressed sound, instantaneously hurling eleven people to the farthest extremities of the room until they came into contact with various walls. The lucky ones hit partitions and went straight through. The unlucky ones collided with solid cinderblock walls. Things broke. Not the cinderblocks.

  Artemis was safe in Butler’s bear hug. The bodyguard had anchored himself against a solid door frame, folding the flying boy into his arms. They had several other advantages over Spiro’s assassins: their teeth were intact, they did not suffer from any compound fractures, and the sonic filter sponges had sealed, saving their eardrums from perforation.

-The Eternity Code, Chapter 1