In The Haunting of Hill House, Eleanor frequently says to herself "journeys end in lovers meeting," a quote from Shakespeare's Twelfth Night, so much so that it becomes a refrain or leitmotif we associate with her. Eleanor is a lonely, damaged woman, for whom the invitation to Hill House offers a new lease on life in the possibility of finding relationship outside the repressive confines of her family. Eleanor is almost desperate as she repeats the mantra that expresses her deepest desire: that this journey end in love for her.
Three ways to explore the theme of Eleanor's quest for love and belonging would be to focus on the three ways she tries to forge a relationship: with Theo, with Luke, and then, sadly—and ironically—with her true "love" in the death that ties her forever to Hill House.
Much has been written about the homoerotic hints in the relationship between Theo and Eleanor. They share bathwater, clothing, and sometimes a bedroom, and sit "shoulders pressed together" to watch the sunlight on a hill. Eleanor wants desperately to escape her loneliness after leaving Hill House by sharing an apartment with Theo, but Theo says she has no interest:
She wants me to take her home with me after we leave Hill House, and I won't do it.
Yet Eleanor persists in her fantasy:
I could help her in her shop, Eleanor thought; she loves beautiful things and I would go with her to find them. We could go anywhere we pleased, to the edge of the world if we liked, and come back when we wanted to.
She also makes more tentative moves towards Luke, trying to engage him in conversation, but she seems to realize her fantasies there won't be realized:
Does he think that a human gesture of affection might seduce me into hurling myself madly at him? Is he afraid that I cannot behave like a lady? What does he know about me, about how I think and feel; does he feel sorry for me? "Journeys end in lovers meeting," she said.
When it becomes clear to Eleanor that her only alternative is going back to her old life, she obtains the "lovers meeting" through a suicide that keeps her at Hill House forever.
A thesis statement could note how lonely Eleanor is and how desperate to find her journey's end in love, so much so that after rejection by Theo and Luke she finally opts for death over isolation.