He is going after his blood.

And Fritz will never be taken alive!" The stars were peacefully shining down on New York City, three days later, when Miss Alice Worthington bade adieu to Doctor Atwater.
The mystery of Randall Clayton's murder had passed into a worn-out sensation, and new crimes, new names, new faces, filled the flaring journals.

The firm hand of Witherspoon was at the helm of the Trading Company, and even Adolph Lilienthal had forgotten his fears.
The Clayton affair had been all threshed out! It had been tacitly arranged between the friends that Witherspoon should watch over Miss Worthington's peace of mind, while Atwater went upon the quest led by the resolute McNerney.
Far away under the shadows of the Katzen Gebirge, on this summer evening, Mr.August Meyer, dogging Irma Gluyas' every footstep, secretly exulted.

"Leah is now on her way to meet me! And then all the old scores will be soon settled!" The Hungarian witch, patient in captivity, breathlessly waited for Randall Clayton's coming, still deceived by the false telegram.
But, as Alice Worthington whispered her last secret instructions to Atwater, sailing on the morrow, her heart was light, for she knew her father, though stained with greed, had been guiltless of Clayton's blood.

"I will give anything on earth to the man who clears Randall Clayton's memory," said the heiress.