"So either panicking amateurs or something critical to defend," Holden said. A metal canister the size of a fist rolled through the gateway, clanking. Amos picked the grenade up casually and tossed it back through the doorway. The detonation lit the room, the report louder than anything Prax had ever heard before. The ringing in his ears redoubled. "Could be both," Amos shouted conversationally from very far away."