His wife's body

Jeremiah sweated as he heaved yet another spadeful of soil out of the ground.  He twisted slightly, throwing the soil behind him, and heard it land with a thud and a rattle on the heap that was slowly growing.  At his feet was now a trench nearly a foot deep and three feet long.  There was much more to dig out yet.
He wiped his eyes with the sleeve of his shirt and drove the spade firmly into the earth again.  The spade sliced through the firm soil, settled and packed, with a metallic crunch.  He bent, putting his weight on the handle, ripping the soil up and heaving out another bladeful.  The soil was clearly undisturbed, and every now and then he doubted his own sanity.  Why on earth was he digging up his wife's grave?
Even as the doubts grew again, the memories pushed them back.  Someone had visited him last night while he was in bed, he'd heard the footsteps shuffling around downstairs, he'd heard the chair in the kitchen pulled back from the table and something seat itself.  He'd held his breath and pulled the thin, cotton sheet over his head, and prayed that the footsteps didn't come to the stairs.  And they hadn't.  He'd lain there, waiting, freezing cold and too terrified to shiver, until he'd heard whatever it was stand up again, rattle the teaspoons in their drawer, and then open the back-door and leave.  And then he'd lain there till morning, till the sunlight was pouring through the bedroom window and he felt like he could face a nightmare because it was daytime.
There'd been mud in the kitchen, small footprints across the tiled floor, and it had pulled out his wife's chair and sat there.  There was even little crumbs of dried mud on the table, as though hands had rested there, clutching a cup of tea, just as she'd like to do when she was alive.  There was even a little mud in the cutlery drawer, scattered over the teaspoons.
It was easier to be brave in the sunshine though, and he'd taken down his shotgun, checked that it was loaded, and gone outside.  There were footprints, faint but unmistakeable, and they'd walked him across the back-fields, alongside the road, and up to the cemetery, where he'd guessed straight away where the footprints must go.  He'd turned back then and fetched his spade as well, and wasn't at all surprised when he found that the footprints did indeed lead to his wife's grave.
He dug down, finally standing in the hole he'd made, rough-cut steps at one end so that he could get out again, wondering how deep they'd buried her the first time.  Then his spade sliced through the soil and kept going, breaking through into space beneath.  Space that should had held a coffin.
He dug over the hole, uncovering a gap that should have contained a rotting wooden box and a corpse.  Soil crashed and broke, scattering on a smooth surface that seemed at odds with the underground, and then, at one end, he found that the hole continued on, burrowing through the head of the grave, underneath the wooden cross and onward into or through the graveyard.  He knelt and poked his head into the hole, and then his shoulders.  He'd have to crawl, but he could fit.  He checked his pockets and found his torch, and wondered only for a moment if there would be enough battery life.  It would be hard to get lost in a tunnel that he had to crawl through.
The tunnel ran straight for thirty yards, descended a little, and then opened out into a stone-walled room.  Shining the torch around him, he realised he was in a crypt, and thinking about the cemetery figured that he must be in one of the mausolea in the centre, where the old families had their ancient monuments and crypts.  In the middle of the floor, broken open in a mass of splinters and wood fragments, was the remnants of a coffin, and grave clothes had been shredded and scattered around.  A yellowing bone that might have been a thigh-bone was all that was left of the body, and there were greasy white deposits that might have been adipocere.
There was no sign of his wife's body.