Instead of adapting the novel, scriptwriter Justin Haythe seems to have read only the book's dialogue—to have typed up all the quotations, then deleted the document down to two hours.Haven't seen the movie yet, but I can see why that'd be a problem. Most of the book's best scenes involve a tension, usually cringe-inducing, between what the characters mean to say and what actually comes out of their mouths, either because they overthink things, or because they miscalculate how their words will come across, or because they're overcome by some fleeting childish urge to hurt, or because—most commonly—they just fail to take the other person into account. At one point, Frank plots out in his mind an entire conversation with his wife, and then gets enraged when she doesn't deliver her hoped-for lines.
Remaining faithful to a text doesn't mean lifting as many lines as possible. This is especially true with Yates, whose characters, if you were to only listen to what they say, vacillate almost exclusively between pathetic and cruel. The heart of his stories, the stuff that lobs a lump in your throat, comes from what the characters think, and then say in spite of it. Take, for instance, the book's perfectly constructed opening scene, the staging of a community play.
"The helplessly blinking cast," Yates writes, "had been afraid that they would end by making fools of themselves, and they had compounded that fear by being afraid to admit it." Gnawing on his knuckles in the front row, Frank watches his wife, initially a vision of the poised actress he fell for, devolve into the stiff, suffering creature who often sleeps on his sofa. After final curtain, he plans to tell April she was wonderful, but then watching her through a mirror as she wipes her makeup off with cold cream, he suddenly thinks twice: "'You were wonderful' might be exactly the wrong thing to say--condescending, or at the very least naïve and sentimental, and much too serious." Frank watches April through the mirror remove her makeup with cold cream. "'Well,' he said instead, 'I guess it wasn't exactly a triumph or anything, was it?'"