Character Analysis
Will Henry's predecessor as Dr. Warthrop's loyal assistant, James Henry left pretty big shoes to fill. Will's father was astonishingly devoted to Warthrop's service, even at the expense of his own family:
It would not be an exaggeration to say my father had worshipped Dr. Warthrop. […] I can state unequivocally that the chief cause of friction between them was the doctor, or rather, Father's feelings for him and Father's intense loyalty to him, a loyalty that trumped all others, including any sense of obligation toward his wife or his only child. That Father loved us, I have never had any doubt; he had simply loved the doctor more. (2.38)
James Henry felt that it was a privilege to serve Dr. Warthrop, and fiercely fought to protect his reputation as a man of science. Even after he contracted the lethal infection with B. arawakus that took his life, he never once alluded to Warthrop as someone to blame. Thus, when Dr. Warthrop took Will Henry in to replace his father's indispensible services, Will Henry took up the mantle of duty with a sense of prideful obligation:
By remaining I honored his memory. Leaving would have invalidated his most cherished belief, the one thing that had made service to the monstrumologist—and the terrible cost of that service—bearable: the idea that Warthrop was engaged in "great business" and to be his assistant meant you, too, were part of that greatness; that, indeed, without you his "business" could not even have approached that exalted level. Running away would have been tacit acknowledgement that my father had died in vain. (7.78)
And with that, we have yet another reason why Will Henry so dutifully tends to Dr. Warthrop. For more on Will Henry's willingness to meet the doc's every whim, swing by his page elsewhere in this section.