Produced by Sankar Viswanathan, Greg Weeks, and the Online Distributed Proofreading Team at http://www.pgdp.net Transcriber's Note: This etext was produced from Astounding Stories March 1932. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed. [Illustration: _Dr. Bird fell back under the ferocity of her attack._] Poisoned Air By Capt. S. P. Meek * * * * * [Sidenote: Again Dr. Bird closes with the evil Saranoff--this time near the Aberdeen Proving Ground, in a deadly, mysterious blanket of fog.] A telephone bell jangled insistently. The orderly on duty dropped his feet from the desk to the floor and lifted the receiver with a muttered curse. "Post hospital, Aberdeen Proving Ground," he said sleepily, rubbing his eyes. A burst of raucous coughing answered him. Several times it ceased for an instant and a voice tried to speak, but each time a fresh spasm of deep-chested wracking coughing interrupted. "Who is this?" demanded the now aroused orderly. "What's the matter?" Between intervals of coughing difficultly enunciated words reached him. "This is--_uch! uch!_--Lieutenant Burroughs at the--_uch!_--Michaelville range. We have been--_uch!_--caught in a cloud of poison--_uch!_ _uch!_--gas. Send an ambulance and a--_uch!_--surgeon at once. Better bring--_uch!_--gas masks." "At the Michaelville range, sir? How many men are down there?" "_Uch! uch! uch!_--five--all help--_uch! uch!_--helpless. Hurry!" "Yes, sir. I'll start two ambulances down at once, sir." "Don't forget the--_uch! uch!_--gas--_uch!_--masks." "No, sir; I'll send them, sir." * * * * * Five minutes later two ambulances rolled out of the garage and took the four-mile winding ribbon of concrete which separated the Michaelville water impact range from the main front of the Aberdeen Proving Ground. On each ambulance was a hastily awakened and partially clothed medical officer. For three miles they tore along the curving road at high speed. Without warning the leading machine slowed down. The driver of the second ambulance shoved home his brake just in time to keep from ramming the leading vehicle. "What's the matter?" he shouted. As he spoke he gave a muttered curse and switched on his amber fog-light. From the marshes on either side of the road a deep blanket of fog rolled up and enveloped the vehicle, almost shutting off the road from sight. The forward ambulance began to grope its way slowly forward. The senior medical officer sniffed the fog critically and shouted to his driver. "Stop!" he cried. "There's something funny about this fog. Every one put on gas masks."