Disclaimer: The world and characters of Harry Potter are J.K's, not mine. Prompt is "nightmare".
xxv. and remember when i moved in you?
Zacharias's nightmares are about The War. Capitalized, because Lucy grows up knowing that The War was horrible and devastating and Should Not Be Talked About. So she doesn't ask him what's wrong, or what he sees, or why he wakes up screaming.
Instead, she holds him. She makes sure she has a cool cloth to wipe his forehead and a cool drink to soothe his throat. Those nights they make love gently, slowly, in a pointed contrast to the panic and fear he remembers from The War. And afterwards they cuddle, even though Zacharias refuses to call it that in the daylight.
Human touch makes his memories seem less real.