He regains his senses in the underground prison.

意识回复的时候他已经在地牢里了。

youdao

To deprive him of sleep, the guards at the underground prison at Hoeryong city near the Chinese border used " pigeon torture".

为了不让他睡觉，会宁市（位于中国边境附近）地下监狱的守卫们使用了“鸽子折磨法”。

youdao

Consider that there were underground millionaire entrepreneurs in the former Soviet Union when owning private property and employing people outside of the state system was a prison offense.

想想前苏联那些地下百万富翁们，当时拥有私人财产并雇用别人来工作可是违法的。

youdao

A.-affiliated black site in Afghanistan by 2002: an underground prison near Kabul International Airport.

NEWYORKER: The Black Sites

Myths that particularly rile prison officials are reports that Supermax, southwest of Colorado Springs, is a dungeon where inmates are cast aside to rot and die, and that the prison is underground, which it obviously is not.

CNN: Reporters get first look inside mysterious Supermax prison

And it was the Middle East-type of prison with the underground rooms for torture.

BBC: Crisis in Syria boosts Kurdish hopes