Nightmare Fuel / Scorpion

• The entire episode "Dominoes," with a little boy trapped in a seaside cave that's filling up with water, and a rock pinning his leg. Hitting the fears of small spaces, water, and the dark all at once? Merry Christmas!
• The conclusion of "Cliffhanger", where 9-year old Ralph, with the noblest of intentions, sneaks into a building slowly filling with sarin gas to seal it off and save lives. He then has to climb out through a partially-cooled incinerator vent, which midway through, restarts behind him like the fires of hell... while his mother watches.
• So, so much of "This Is the Pits". First, a woman is trapped in her car at the bottom of the LaBrea Tarpits and is rapidly running out of breathable air as her car fills with fumes. When they try cabling the car up and easing it out, the car proves to be too firmly stuck, and the damage makes the car start filling up with liquid. The only solution is to pull her out through the tar water and just get her to the surface as quickly as possible. But when Happy starts winching them up, Walter screams; his feet are stuck in the tar and he's being pulled apart. He has to undo his safety line so the woman can be pulled to safety before she suffocates, leaving Walter alone and untethered in the pits with almost no air. He ends up using a road flare from the car to set the tar around his feet on fire to free himself.
• "Don't Burst My Bubble" climaxes as a girl with no immune system is entombed in a vat of honey (It Makes Sense in Context), then put into an emptied meat locker by the team as a substitute for her sterile bubble environment. Only, to sterilise the meat locker properly, they have to set it on fire WHILST SHE'S INSIDE IT.
• In-universe in "Dirty Seeds, Done Dirt Cheap", when Cabe, Happy, and Sylvester accidentally inhale ergot and start hallucinating about their worst fears come to life. Sly's hallucination is chickens (and associated diseases), Cabe's is aging, and Happy's is rejection.
• "Maroon 8" picks up directly after the previous episode, which had the team's plane going down. After they make it so they can land (relatively) safely, the pilot commands Happy to leave the cockpit, where she's been acting as copilot. After the crash, they reach the sheared-off cockpit, and she sees that her seat was impaled by a huge piece of metal. She remains visibly disturbed for some time.
• Walter's accident in "A Christmas Car-Roll" is more terrifying in its way than the terrorists, epidemics and disasters the team usually faces, precisely because it's so ordinary. He carries a box of equipment downstairs and trips on a stray cable, banging his head on the concrete. Florence finds him in a pool of blood, and if she hadn't chosen that moment to stop by, he'd have been dead in a few minutes. Chilling.
  • Happy relieving the pressure in Walter's skull by drilling into it. So painful it creeps into his coma dream.

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