In a hell where "only bones enter, no flesh leaves," how much of his own flesh will a father sacrifice to save his son?

In the sweltering summer of 1944, a 65-year-old illiterate farmer named Zhao Defa is thrown into a living hell. Lushun Prison is a demonic lair designed to grind men into dust, known to locals as a place where "only bones enter, no flesh leaves". Within the suffocating, 60-degree red-brick kilns, Defa miraculously reunites with his son, Zhao Tiezhu—an anti-Japanese resistance fighter now crippled and brutally disfigured by his captors.

To secure his son's survival, Defa joins a group of death-defying inmates to secretly dig through an abandoned ventilation shaft. When their escape plan is nearly exposed, the elderly father makes the ultimate sacrifice: he takes the blame, enduring unimaginable tortures like bamboo splinters, branding irons, and the flesh-tearing "King of Hell's Whip" to protect the tunnel's secret.

Enter Medical Officer Sato, a twisted Japanese doctor traumatized by his own cold, samurai father. Believing paternal love is a hypocritical lie, Sato secretly provides the prisoners with keys to their heavy shackles, orchestrating a cruel "live experiment". He intends to watch the father and son betray and abandon each other at the threshold of life and death.

As the tunnel collapses and pursuing Japanese bayonets close in, they face an impossible choice. Will survival instincts shatter their bond, or will a father's love forge a miracle out of blood and ashes?

The Imperishable Will is a harrowing, blood-soaked epic of survival, unbreakable family bonds, and the triumph of the human spirit in the darkest of abysses.