Esteemed gay critic Daniel Mendelsohn, who, at 15, became Mary Renault's 'young American' pen pal, has a video chat with the New Yorker

Band of Thebes has much more about this.

At the stair-foot Hephaistion was waiting. He happened to be there, as he happened to have a ball handy if Alexander wanted a game, or water if he was thirsty; not by calculation, but in a constant awareness by which no smallest trifle was missed. Now, when he came down the stairs with a shut mouth and blue lines under his eyes, Hephaistion received some mute signal he understood, and fell into step beside him.

— Mary Renault, Fire from Heaven