Ishmael hadn't realised how bad he had gotten until he stumbled upon the crack in the earth behind his tired little shelter. He had eased down onto his white belly, like he taught his students to calm them whenever a tremble ran under their feet, but instead of shuffling back to safety, he'd leaned forward.

   A trickle of water escaped the surface in a drip off an overhanging edge of the crack. Drop by drop, it drew the eye down into a spiralling, vertigo view of lush green caverns. If he flared his nostrils, he could catch a whiff of loam and that dark, quickening scent of ancient things beneath it. The caverns breathed out, a breeze puffing up to tickle his nose, and he saw himself as if from below; a pale face hanging over the rock to ogle. Was the rock thick beneath him, he wondered, or would he hear it crumble if he leaned just a little farther?

   "Sir?" Ishmael's ears pricked up at the voice of the chattiest foal in his class this season behind him. "That weird gravedigger horse is back in town for supplies and my ma wants you to tell her if the stuff he's offering is worth… what are doing? Are you- "

   Ishmael looked over his shoulder in time to see the little bay snort and flatten herself to the ground as if shoved down by the hoof of a sky god. Wide brown eyes stared back at him. Ears pressed flat. Guilt gave Ishmael the kick in the rear that common sense had failed to. He wriggled back a few strides to where she lay, then stood and nosed her up onto legs that looked as wobbly as he felt.

   "It won't bite, I promise," he said, "As long as we're careful. Do you think you could help me find some rocks to pile up as a warning until we can cover it properly?"

   The foal shot off, head held high with purpose. Ishmael, for his part, pushed over the big rock that his sister had once used as the centre of her butterfly garden, back when they had shared a roof. Without it sitting out front, his shelter was even less of a home, but Ishamel was now certain he wouldn't be sleeping there for a while anyway. He was embarrassed at having missed the restless gloom creeping up on him, making lessons seem twice as long and skies half as bright, but now that he recognised his old enemy, he would waste no time curing it. In the Buried Kingdom, one place never failed to bring life sharply back into focus.

   When enough stones had been gathered and Ishmael had made appropriately impressed sounds at his student's contributions, he asked to be led back to the horse in town for supplies. The foal delivered an extensive account of the stranger's trading goods as they trotted along.

   "What makes your mother think I'll know the worth of these Dungeon finds?" Ishmael asked, interrupting a delighted description of some creature's oversized eyeball when it became apparent the foal did not intend to pause for breath.

   "You've been in the Dungeon before, haven't you? Loads of times. Isn't that how you got your scar?"

Scar was being generous to the nick in his left ear. "I've been down twice. The horses of House Vesperal - the gravediggers - practically live there. If you want to figures added up, by all means, ask me, but a clever horse would take their word over mine when it comes to anything from the Earthen Furnace or deeper."

   "See, you know all sorts of things about the Dungeon!" They were mere strides away from the foal's home now, and she was giddy with success. "Where's House Vesperal?"

   "It's not a place, it's a family. I've never met one but I understand they return the bones of lost horses to their next of kin. Something to do with spirits too - I never learned exactly what." Ishmael saw the foal's eyes widen with gory possibility and hasted to add, "I'm sure it's all very respectful."

   "We do our best," came a voice from behind. "Though some spirits can get pretty wild before they calm down."

   A chestnut paint with dust up to his elbows winked at the foal. Her mother stood nearby the stranger, nosing through a heap of trinkets and creature parts. Both heap and stranger smelled like the breeze from the crack and, for the first time in months, Ishmael felt his heart beat faster.

   "You must be the Vesperal. I'm Ishmael. I've been down myself a few times - merchant caravans, mostly. Top-level. I like the work." He could hear himself speaking too quickly, but not stop it. "Will you return soon?"

   The foal's mother spared him a glare that said she suspected an impromptu break in the season's lessons was forthcoming and did not appreciate it. The stranger was polite enough to only dip his head in greeting.

   "Dirge, at your service. If I can stock up here, I'll start my next descent this time tomorrow. Always more bones waiting to see the sun again, I'm afraid."

   "May I come? That is to say, do you have room on your expedition for one more?"

   The foal squealed. Dirge gave an amused snort.

   "I'll have to check if anyone's dropped off the waitlist," he said, but Ishmael's plummeting heart must have shown on his face because Dirge's nostrils flared, "That was a joke! No-one outside the House ever wants to come."

   "I do. Very much."

   "Are you quick at digging? Can you tell the difference between horse bones and the bones of… other things?"

   Ishmael tried to imagine carrying the dried, brittle bones of dead horses through the caverns that had killed them. It put a shiver in him, but didn't dull the urge to go. The what of the venture wasn't nearly as vital as the where.

   "I'm a quick study."

   "Well… " Dirge's jaw moved as he thought it over. It was excruciating. Who knew when another party bound below would pass through town if the Vesperal didn't want him? "As long as I can resupply…"

   The foal's mother sighed. "If Ishmael is this eager to go with you, that's enough vouching for me. You have your trade, gravedigger."

   Dirge turned a sunny, if not mildly confused, expression on Ishmael. "The more the merrier, then. When can you leave?"

   "Today." The fearful tension was leaving his muscles now, making room for the buzzing squeeze of anticipation.

   "I'm coming too!" the foal whinnied, only to quiver in outrage when all three grown horses nickered. "It's not fair, you can't just leave."

   Ishmael had heard that note before, from his own throat as well as others'. It didn't change his plans - he'd learned in adolescence that when these dark moods came, they were best returned to the Dungeon, lest they fester - but it sobered him enough to nudge her shoulder. "I'm sorry. I'll be back before you know it." The crack flickered through his mind again; that siren song smell. "And first, let me seal up that hole like I promised."