Almost before the echoes of Eradicate¹'s direful warning cry had died away, Tom was on his way out of the house, pausing only long enough to slip on a pair of shoes and his trousers. There was but one thought in his mind. If he could get the Humming-Bird safely out he would not care if the shed did burn, even though it contained many valuable tools and appliances.  
"We must save my new aeroplane!" thought Tom, desperately². "I've got to save her!"
 
As he raced through the hall he caught up a portable chemical fire-extinguisher. Tom saw his father's door open, and Mr. Swift looked out.
 
"What is it?" he called anxiously.
 
"Fire!" answered the young inventor, almost before he thought of the doctor's warning that Mr. Swift must not be excited. Tom wished he could recall the word, but it was too late. Besides Eradicate, down in the yard was shouting at the top of his voice:
 
"Fire! Fire! Fire!"
 
"Where, Tom?" gasped³ Mr. Swift, and his son thought the aged⁴ inventor grew suddenly paler.
 
"Aeroplane shed," answered the lad. "But don't worry dad. It's only a small blaze. We'll get it out. You stay here. We'll attend to it—Mr. Jackson and Eradicate and I."
 
"No—I'm going to help!" exclaimed Mr. Swift, sturdily. "I'll be with you, Tom. Go on!"
 
The lad rushed down to the yard, closely followed by the engineer, who had caught up another extinguisher. Eradicate was rushing about, not knowing what to do, but still keeping up his shouting.
 
"It's on de roof! De roof am all blazin'!" he yelled.
 
"Quit your noise, and get to work!" cried Tom. "Get out a ladder, Rad, and raise it to the side of the shed. Then play this extinguisher on the blaze. Mr. Jackson, you help me run the Humming-Bird out. After she's safe we'll tackle the fire."
 
Tom cast a hurried look at the burning shed. The flames were shooting high up from the roof, now, and eating their way down. As he rushed toward the big doors, which he intended to open to enable him to run out his sky racer, he was wondering how the fire came to start so high up as the roof. He wondered if a meteor could have fallen and caused it.
 
As the doors, which were quickly unlocked by Tom, swung back, and as he and the engineer started to go in, they were met by choking fumes⁵ as if of some gas. They recoiled⁶ for the moment.
 
"What—what's that?" gasped Tom, coughing and sneezing.
 
"Some chemical—I—I don't know what kind," spluttered Mr. Jackson. "Have you any carboys of acid in there Tom, that might have exploded by the heat?"
 
"No; not a thing. Let's try again."
 
Once more they tried to go in, but were again driven back by the distressing⁷ fumes. The fire was eating down, now. There was a hole burned in the roof, and by the leaping tongues of flame Tom could see his aeroplane. It was almost in the path of the blaze.
 
"We must get her out!" he shouted. "I'm going in!"
 
But it was impossible, and the daring young inventor nearly succumbed⁸ to the choking odors. Mr. Jackson dragged him back.
 
"We can't go in!" he cried. "There has been some mysterious work here! Those fumes were put here to keep us from saving the machine. This fire has been set by some enemy! We can't go in!"
 
"But I am going!" declared Tom. "We'll try the back door."
 
They rushed to that, but again were driven out by the gases and vapors⁹, which were mingled¹⁰ with the smoke. Disheartened, yet with a wild desire to do something to save his precious craft, Tom Swift drew back for a moment.
 
As he d............