“Well, then, Mr. Shei’s orders are that you are to inoculate the young lady with the laughing fever. You will calculate the dose just as you did in the cases of the seven millionaires. The Phantom will be told that the antidotes will be administered on the one condition that he goes back to his bailiwick and keeps his hands out of Mr. Shei’s affairs. That will keep him on his good behavior for a week, and by that time Mr. Shei will have cleaned up.”
“And the young lady?”
Slade laughed unpleasantly. “She knows too much, as I have already told you. A little knowledge is a dangerous thing. Much knowledge is apt to prove fatal. You will merely forget to administer the antidote when the time comes.”
Doctor Tagala gave a rumbling laugh. Helen felt a sudden chill. She leaned weakly against the wall. Inoculation with what Slade had called the laughing fever seemed far more dreadful than death itself.
“By the way, doctor,” Slade went on, “I hope the antidote is safely hidden?”
“You may rest assured on that point,” Tagala declared. “I have hidden it so securely that not even Mr. Shei knows where to find it.”
“Good. That being the case, our seven millionaire friends would be in a bad fix if a sudden misfortune should befall you.”
“Nothing on earth could save them,” said Tagala emphatically. “The secret is in my exclusive possession. No other man could diagnose the malady, much less prescribe a remedy. The lives of the seven gentlemen are absolutely in my hand.”
“Then there isn’t the slightest chance of Mr. Shei’s plans falling through?”
“Not the slightest. The seven gentlemen will pay Mr. Shei’s price, and within a week we shall all be rich beyond the dreams of avarice.” The gloating tones hinted that Doctor Tagala’s imagination was luxuriating in enchanting visions. “By the way, when do we inoculate the young lady?”