Fenton Q. Harcourt is an obese, skeptical and serious individual, never wanting to fund any research on myth and legends such as Atlantis. He believes Milo's grandfather wasted his potential on his search for the lost city and believes Milo is doing the same. When Milo tries to propose funding an expedition to Atlantis, in order to not let the board of directors be annoyed with Milo's theories about the city, Mr. Harcourt purposely moves the meeting without telling Milo to cancel it. He also teases Milo by saying that the museum would need him in winter to check the boilers when he tells him he has potential with them.
In spite of his mean attitude, however, Mr. Harcourt acts reasonably for an experienced businessman: his refusal to fund down an expedition to Atlantis is partly due not wanting to risk wasting money if the city turned out to be just myth. Additionally, Harcourt really believes that Milo has a great potential, but comes to belittle him when Milo refuses to hear him and insists on Atlantis' existence.
Not wanting to bother the board of directors with Milo's wild theories, he moves around the times for Milo's presentation to deliberately make him late and cause the presentation's cancellation. Milo quickly rushes upstairs after getting his messages and ends up pursuing Harcourt outside, threatening to quit if Harcourt doesn't take his proposal seriously and grant him funding. He mockingly tosses him a nickel and tells him to take a trolley to the Potomac to jump in and clear his head. After this final act, Harcourt rides off in his car, splashing Milo with water, leaving him depressed and dejected.
He doesn't appear for the remainder of the film. This encounter would be the last time the two would ever see each other, as Milo would stay behind in Atlantis after he helped discover it.