Directed by Jeff T Thomas
Written by Anthony E. Zuiker, Ann Donahue, Carol Mendelsohn & Trey Calloway
"The Triangle" is the 10th episode of Season 5 and the 102nd overall. It originally aired December 10, 2008.
The team investigate an armored car heist in which a guard is killed. Mac is questioned by the FBI regarding the flash drive missing from the evidence locker. Danny proposes to Lindsay.
Tropes for the episode:
- Autopsy Snack Time: Sheldon admits to Sid that the "no eating in the morgue" policy never stopped him from "sneaking in the occasional bag of popcorn."
- The Bermuda Triangle: Referenced when Mac disappears from the area around the Empire State Building known for bizarre happenings. In this case, a security guard was electrocuted to death while alone in the back of an armored car robbery just prior to it being robbed. Once they debunk the theory:Mac: We may be guilty of creating an urban legend, but there's no way this building is guilty of murder.
- Daddy's Little Villain: The culprit in the heist case is the adult child of a former criminal, and is following in his footsteps to the point of using a signature invention of his.
- Deconfirmed Bachelor: After telling Mac four seasons earlier in "Til Death Do We Part" that he didn't believe he'd ever fall in love, Danny realizes he truly does love Lindsay and proposes to her.
- Honorable Marriage Proposal: Lindsay believes Danny is proposing because she's pregnant.
- I Have This Friend: Lindsay asks Stella whether the chemicals in the lab would affect a baby, as says she's asking for a friend of hers who works in the New Jersey Crime Lab. Stella gives her reassurances due to all the safety precautions they use... then tells her to congratulate her friend.
- Internal Reveal: Lindsay and Danny tell Mac about the pregnancy. Stella also figures it out during her and Lindsay's "I have this friend..." conversation, and the rest of the team is told in between this episode and the next.
- Rejected Marriage Proposal: Lindsay turns Danny down because she doesn't want him to feel trapped.
- Reverse Polarity: Adam shows Lindsay how the magnetic device used in the heist works by reversing the polarity of the magnets, which makes a vault door unlock.
- Sdrawkcab Name: Used as an inside joke. The man whom Danny & Stella question is named Yert Yawallac, which is the episode writer's name spelled backwards. Trey Callaway also served as one of the series' producers.
- Suntan Stencil: Done intentionally in this case. The team find a small pineapple-shaped sticker on the sleeve of a murdered armored car guard. It's winter-time so when they find traces of sunscreen on it, Lindsay realizes that it's for making a "tan-too". The perp had worn it in a tanning bed to produce the shape on her skin, forgot to remove it, and it fell on the victim at the scene.
- Talkative Loon: In the opening, a seemingly disturbed young man is wandering the streets, having a conversation with himself about hearing frequencies. Later, Mac, Stella and Danny spot him interacting with a suspect in video footage and track him down. While Stella & Danny question him, he jabbers away and when they're done he wanders off, having his frequency conversation again.
- Title Drop: Various characters say things like "The Triangle strikes again" when conversing about the area around the Empire State Building where cell phones, radios, etc. lose signals and other odd things have been reported to happen.
