This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Tom Clancy
Without Remorse gives the reader a lovingly detailed description of what repeated sudden decompression can do to the human body, when John Kellynote later known as John Clark uses an old US Navy presurization chamber to politely question a drug dealer (among other crimes) who was involved with the death of Kelly's girlfriend.
There's another one in The Teeth of the Tiger: the reader gets a play-by-play of the death of a playboy financing terrorist operations. While it doesn't look like anything other than a heart attack to the casual observer, everything that goes on inside his mind is enough to make you paranoid about feeling pricks on your posterior.
Locked On where a group of Dagestani terrorists re-purpose space rockets and turn them into nuclear missiles,they destroy a part of Moscow before John Clark and Spetsnaz Alfa break into the missile command station and kill them all.
The Animal Wrongs Group of Rainbow Six plan to use a modified version of ebola to infect the Sydney Olympics, then send out the virus masked as a vaccine in the hopes of wiping out the human race. That's not the nightmare part though, the nightmare part is loving detail is given of the utter hatred and scorn those in the project have for humans. Paraphrased:
When having to put down dogs while working as a vet she would cry and be unable to sleep for a week. Watching the last of the test subjects die she hoped that she would not be late home after dumping the bodies, there was a nature program she wanted to watch. "May as well get it over with and dispose of these filthy humans in the incinerator."