Sometimes Jack visits Gray.
Ianto sees him, entering the morgue and sitting cross-legged underneath his brother's drawer. Sometimes Jack reads old children's books, out loud, in a small, piteous voice that Ianto knows doesn't belong to his captain. Sometimes Jack sings softly, alien songs that Ianto doesn't know, or sometimes earth songs he knows very well. Sometimes, when he knows Jack cannot hear him, Ianto sings too.
Sometimes Jack cries, silent tears sloping down his face.
Ianto feels as though he's intruding on something very private and so he leaves, closing the door behind him until it emits a soft click.