The emotional arc is properly built.
The son of the American president falls for a British prince. The premise sounds like it should be ridiculous and instead it is completely, helplessly charming. McQuiston writes banter that actually crackles — not the kind that reads as two characters taking turns being clever, but the kind where you feel the specific electricity of two people who cannot stop talking to each other. The emotional arc is properly built. The ending is the ending it had to be. I have recommended this to twelve people. Ten of them texted me within a week.