The film centers around Jane and Jefferson Blue, a husband-and-wife team of spies who are taking some maternity leave time to vacation in New Orleans with their 8-month-old daughter. While enjoying the tourist attractions of The Big Easy, they are stalked by a petty thief and mugger with delusions of grandeur (and competency), tailed by a bumbling pair of New Orleans Police Department detectives who only want to help, but are way out of their depth... and they stumble upon a devious plot involving an insane female arms smuggler and a large quantity of high-tech explosives.
Tropes seen in Undercover Blues:
- Accidental Misnaming: "Not Morty! MUERTE!" And then subverted near the end of the film when Jeff and Muerte have been captured by Paulina's men; Jeff calls him "Muerte" and acts as if he's really The Man Behind the Man, at which point Muerte insists, "My name is Morty!"
- Action Mom: Jane Blue. To quote her husband, "Jane's an expert in martial arts even I can't pronounce. She can kill you seven different ways without using her hands."
- Badass Family: The Blues.Jane Blue: You brought our baby into a knife fight?
Jeff Blue: It was a fair fight. Two of them, two of us...
- Badass and Baby: The afore mentioned knife fight.
- Bad Cop/Incompetent Cop: The two cops. They are very, very driven to follow the Blues around and find out what kind of CIA business they are doing (even if the Blues (especially Jeff) insist that they aren't agents), maybe help if they can... and they pretty much annoy their chief, the Blues, and are totally unable to suspect that there's a bank robbery going on right across the street even after Jeff points out the getaway car and how it's sticking out like a sore thumb.
- Battle Couple: The Blues, of course.
- Berserk Button: Calling Muerte anything other than Muerte. Especially calling him "Morty".
- The Big Easy: Of course.
- "Facing the Bullets" One-Liner: Several goons pull guns on Jeff and tell him to not make any sudden movements. "Why not, is there a bee on me?"
- Good Cop/Bad Cop:Jeff Blue: I never get to be bad cop.Jane Blue: That's because you could never keep a straight face.
- Guile Hero: Jeff Blue
- Hair-Trigger Temper: Muerte's answer to everything that annoys him is to pull out a switchblade and try to stab it. Unfortunately for him, "everything that annoys him" during the movie are the Blues, so all he gets in response is a Curb-Stomp Battle Humiliation Conga.
- Happily Married: Despite a few disagreements about, e.g., taking the baby into dangerous situations, the couple is one of the finest examples of Happily Married to be spotted in an action film. Their easy camaraderie is an enjoyable counterpart to the danger they're facing.
- Hello Again, Officer: The reason the cops become obsessed with the Blues is because pretty much from the moment they arrived to New Orleans they become embroiled on a bunch of situations that attract police attention (starting with pummeled muggers and escalating to stopping a bank robbery, a fight on a restaurant (that was full of enemy agents), finding a corpse on a cemetery and more).
- I Take Offense to That Last One!:Jane Blue: Jeff's a lousy shot. He had to bribe the examiner at the FBI.Jeff Blue: That's a lie. I bribed the guy at the CIA. I *blackmailed* the guy at the FBI.
- Improbable Weapon User: Jeff Blue beats up several muggers...using a baby stroller as his only weapon...and carrying his infant daughter in his other hand.
- Later, he stops a bank robbery in progress by booby-trapping their getaway minivan with the chain from the fence around the parkway.
- Ineffectual Sympathetic Villain: Muerte takes on an almost Wile E. Coyote level of the audience's pity by movie's end.
- Insistent Terminology: His name is Muerte, and don't you forget it.
- Interrogation by Vandalism: Jeff forces the Big Bad to surrender by threatening to set the C-12 on fire. Then again, the C-12 has been established to be an incredibly powerful explosive and Jeff's threat threatening is pretty much a Taking You with Me.
- Jack Bauer Interrogation Technique: Monkeywrenched the hell out of. Jane's baby crying in the next room is used to terrify a suspect into confessing before the torture even begins.
- Large Ham: Fiona Shaw and Stanley Tucci between them chew more New Orleans scenery than Hurricane Katrina did.
- MacGuffin: The C-12. An explosive so powerful that the United States military refuses to use it... probably because it's as unstable as it is powerful.
- Mandatory Unretirement: The Blues are not working for the CIA anymore... officially. They still got contacted to work on the C-12 assignment.
- Miranda Rights: Played with a bit in the following exchange:Jeff Blue: FBI! You're under arrest. You have the right to remain silent. If you give up that right you may talk, sing, dance, impersonate Elvis or anything else you like. You have the right to an attorney. If you're broke and can't afford one, tough shit! Now get in the car, you suspected felon, you!
Mr. Ferderber: Wait, wait. What am I being charged with?
Jeff Blue: That's for me to know and you to find out.
- Mugging the Monster: Muerte is the patron saint of this trope.
- Noodle Incident: Several past missions are alluded to with few details given, but they were apparently amazing adventures. Assuming, that is, that any of them actually happened.
- Not My Driver: Jeff Blue even lampshades this by saying, "No one ever looks at the driver," after he foils a bank robbery in progress by booby-trapping their getaway minivan and taking the place of their driver.
- Police are Useless: Or at least waaaay out of their depth when dealing with international espionage.
- Something Blues
- Teeth Flying: Used as a Running Gag. Poor Morty's gonna need a full false denture in the epilogue...
- Xanatos Gambit: Jeff's modus operandi. Planning for every outcome is how a spy stays alive.
- Xanatos Speed Chess: Of course, it helps to know how to change your plans very quickly.