Old Master Zhang was a man from Shanxi.

Because his daughter was marrying, the whole family journeyed south to the Jiangnan region to prepare her dowry.

When their boat reached Jinshan, Old Master Zhang crossed the river ahead of the others, instructing his family to wait on the vessel and strictly forbidding them from cooking any fish or meat, as a monstrous giant turtle (Yuan) resided in the river.

This creature possessed an acutely sensitive nose; every time it smelled cooked meat, it would rise up, stir the waters into a frenzy, capsize boats, swallow people whole—a menace that had plagued the area for ages.

After Old Master Zhang left, his family forgot his warning and illicitly began roasting meat in the cabin.

Suddenly, colossal waves roared up from the river, overturning the boat, and his wife and daughter were swallowed by the cold depths.

When Old Master Zhang returned and found his family gone, he knew they had been killed.

Overwhelmed with deadly grief and rage, he immediately hastened to Jinshan Temple to seek an audience with the old monk, hoping to glean information about the Yuan monster so he could seek vengeance and slay it once and for all.

Upon hearing the tale, the old monk was aghast. "That Yuan monster is savagely fierce," he whispered. "We have lived beside it for many years, constantly suffering its persecution.

To ensure our own survival, we have no choice but to worship it as if it were a deity.

Periodically, we must slaughter oxen, sheep, and pigs, and cast half of the carcass into the middle of the river.

Each time the Yuan feeds, it swallows the offering whole in a single gulp and then departs without a trace.

Who among us dares to oppose it?" Old Master Zhang listened intently, deep in thought.

Finally, he devised a brilliant strategy to deal with the Yuan.

He summoned a contingent of blacksmiths and had them construct a furnace on the mountainside to forge iron, heating lumps weighing over a hundred jin.

Once he pinpointed the stretch of river the Yuan frequented, he directed several robust men to work together, using massive iron tongs to heave the searing hot iron blocks into the water.

The Yuan leaped out, swiftly gulping down the glowing metal.

Not long afterward, the river surface churned as if mountains were rising and falling, but in the next instant, the turbulence subsided, leaving the water calm.

Peering intently, they saw the carcass of the great Yuan monster floating dead on the surface.

Passing merchants and the monks of the temple, upon hearing the news, all clapped their hands in celebration.

They contributed funds to construct a memorial shrine for Old Master Zhang, hanging his portrait there for prayer and veneration, and it was said that these devotions were remarkably efficacious.