Edward Powell, the poor young man, has been forced through financial circumstances to share a country home with his Aunt Mildred. She is, alas, not the sophisticate he deserves for a relative; she actually likes living in the country and gardening and taking long walks for no reason at all. She finds his French novels "smutty" and refuses to fix a settlement on him from the family trust. And so, Edward is forced to live in remote Llwll (pronounced roughly "Thoolth;" it's Welsh, so the "w" is a vowel).
Finally, Edward reaches his breaking point. He writes in his journal, "I should be very much happier if my Aunt were dead," and we follow him through several attempts to do Aunt Mildred in.
Hull's novel is (unsurprisingly) old-fashioned, and its twist ending isn't much of a surprise today, though it might have been a shocker 75 years ago. But Edward and Mildred are delightful characters, each set in their ways and neither willing to compromise on much of anything. The book is droll and witty, and I found it a charming little diversion.