* AngstWhatAngst: "The Hottest Greetings" shows Kholodov and Shustov responding surprisingly calm to news that [[spoiler:Granin was burnt alive]]. Even Berezin, who never knew [[spoiler:him]], shows more emotions than them.
* {{Anvilicious}}: "The Lost Little Ones" is not subtle about its aesop: "Panhandling is bad, and using babies for it is beyond bad". The message is delivered by Antonova (mother of four and FriendToAllChildren) and, in general, it depicts a serious problem, so [[TropesAreTools it looks justified]].
* ArchivePanic: More than 2700 episodes in 15 years span. Hopefully, all episodes are uploaded on series official Youtube channel.
* BrokenBase: There is visible split between fans who prefers StrictlyFormula procedural, and those who want the series to be CrimeTimeSoap with main focus on FES squad members' personal lives.
* CompleteMonster:
** "The Pit Snake's Bite": [[VillainWithGoodPublicity Vyacheslav Volkov]], at first only known as the Organist, is a successful psychotherapist who is inspired by a book about an ancient [[ReligionOfEvil deadly cult]] to [[SerialKiller kill]] eighteen [[WouldHurtAChild children]]. Volkov kidnaps and fatally poisons 17 kids, cutting out the kidneys and liver of each victim to leave no trace of the poison. At the same time, Volkov frames one of his patients and eventually pressures him into confessing to the murders. On the run with his eighteenth already-poisoned victim, Volkov is intercepted by the [=FES=] and shoots Kruglov with a poisoned dart. Even then he brags that, being TheSocialExpert, he will weasel his way out of prison, so Maysky, in the chaos, stabs him with one of the remaining darts and lets him die of the same poison Volkov used for his killings.
** "The Roma Woman": [[PoliticallyIncorrectVillain Stepan Vorobyov]] is a crime boss and a leader of a small but brutal gang who frightened the witnesses at his trial into silence and got a much lighter sentence than he deserved. Stepan [[FalselyReformedVillain pretends to be a reformed, respectable man]], but never really changes, [[AbusiveParents mentally tormenting his son Andrey]]. After learning Andrey has a [[UsefulNotes/{{Romani}} Roma]] girlfriend, Stepan threatens to burn the entire Roma camp unless he breaks up with her. When Andrey refuses, Stepan makes good on his threat and not only burns down the camp but stands by with his goons and [[SinkTheLifeboats shoots the survivors who try to flee]], killing at least 18 people this way. Stepan bribes the government and the police into recording all the deaths as accidental, and Andrey's girlfriend Nina, the only one to escape the massacre, later remarks that Stepan isn't human at all.
** "Silence": [[AbusiveParents Maxim Brusnikin]] is a wealthy businessman whose daughter was seemingly kidnapped four years ago. In fact, Maxim held her hostage in his house, all the while he was hiding behind a mourning father's façade. Maxim has two kids with his own daughter while [[ParentalIncest constantly raping her]], one of whom is a newborn baby [[OffingTheOffspring he kills]]. Maxim murders the people who [[HeKnowsTooMuch suspect something about his daughter missing:]] his daughter's ex-boyfriend, the mother of said boyfriend, the state prosecutor who investigated her case, and his own son.
** "Night Witness": [[SerialKiller Dmitry Tsukanov]] is a [[KillerCop sadistic police officer]] who sees himself as a [[KnightTemplar crusader against filth]]. His M.O. is [[SerialRapist raping sex workers]] and killing them by driving over them with his SUV, making his victims run. Claiming four victims this way, Tsukanov [[CopKiller murders another policeman]] and shoots up a police precinct, killing and endangering several people to eliminate the one witness to his crimes.
** "The Dead Hour": [[WouldHurtAChild Gleb Khovrin]] is a spy planning to sabotage a priceless hybrid plant at an institute of biotechnology. For that purpose, Gleb gets a job at a children's camp organized by the institute and tells two [[UnwittingPawn unsuspecting boys]] to release several bees--carrying a virus that would kill the hybrid--into the institute's greenhouse. When they falsely tell him that they did it, Gleb decides to LeaveNoWitnesses and escape: he drowns the camp's director, with whom he slept to gain her trust, and then infects the entire camp with a genetically-modified cholera Vibrio that nearly kills the children and staff and almost starts a nationwide epidemic. Gleb is killed in a confrontation with the [=FES=], but not before fatally shooting a 9-year-old ChildProdigy--the one who figured him out first and prevented the sabotage--when the latter [[TakingTheBullet takes the bullet]] to protect his friends.
** "The Sign": [[EvilGenius Max]] is a brilliant biologist. He marries [[BrokenBird Natasha]], who has escaped a totalitarian cult, and learns that as the cult leader's stepdaughter, she is set to inherit a lot of money. [[InheritanceMurder To get his hands on that money]], Max infiltrates the cult and uses bacteria culture to write signs on the walls. When the signs appear, the cultists believe them to be signs from Heaven and die in a mass suicide. Since the cult leader's sister manages to escape, Max captures her and chains her up in the cold to die, so that she wouldn't claim any part of the inheritance. He infects his wife, who loves and trusts him completely, with a rare lethal disease, and believes that as a genius of science, he is AboveGoodAndEvil.
** "The Dead Wedding": [[WomanScorned Darya Ugreyeva]] is Oleg Muranov's girlfriend. When he dumps her, she decides to [[DisproportionateRetribution frame him for mass murder in revenge]]. Oleg has delivered several boxes of wine to a lavish wedding, so Darya substitutes part of the bottles with [[TamperingWithFoodAndDrink poisoned]] fake wine, killing 34 people. Seven years later, posing as a schoolgirl, Darya is tracked down by Oleg's stepsister and kills both her and [[CopKiller a policeman]] who tries to help her. Fearing the [=FES=] are on her trail, Darya tries to escape again, and to ensure she would LeaveNoWitnesses, she poisons the berry drink at the school canteen, landing several staff members in intensive care and setting the scene for the possible death of hundreds of children.
** "Triumph": [[WolfInSheepsClothing Oleg Nikiforov]] is a seemingly unassuming young man from a family of rich businessmen who defrauds multiple people out of money and [[FrameUp frames his uncle]] for it. Afraid of getting sued by his uncle, Oleg decides to kill both [[LeaveNoWitnesses the latter]] and [[InheritanceMurder Oleg]]'s own [[{{Patricide}} father]]. Oleg manipulates party organizer Krasikov into filling balloons with sarin, killing the intended victims and 22 more people at a birthday party. Oleg has one of his fraud victims, Zudin, frame and kill Krasikov, and then murders Zudin himself. Oleg frames his mentally disabled sister Maryana as the crimes' mastermind, planning to get her institutionalized and mooch off of her inheritance forever.
** "Black on White" two-parter: [[SerialRapist Grigoriy Zubkov]] is a [[WouldHurtAChild pedophile]] who marries women with teenage daughters in order to molest the daughters. Having done this to at least five families, Zubkov has Viktor Lysenko assault his stepdaughter Tatyana Belaya, prompting her to leave her hometown so Zubkov can sexually abuse her younger sister [[DrivenToSuicide to the point of her suicide]]. Zubkov kills Lysenko for [[YouHaveOutlivedYourUsefulness outliving his purpose]] and when Tatyana, now an FES Detective, investigates his death, Zubkov attempts to murder her.
** "Houris of Our Town": [[SerialKiller Nikifor Yushkin]] is a bookkeeper who hires a prostitute named Ulyana Anisimova, assaulting her when he saw scars on her fingers. After Ulyana fights back and escapes, Nikifor tortures and murders women out of resentment, possibly raping them and mutilating their fingers to resemble Ulyana's scars. Nikifor keeps 12 of his victims in a garage, and tracks down Ulyana to murder her before his demise.
** "The Lost Little Ones": Mikhalych is a ruthless crime boss with female beggars under his control. For the purpose of child begging, Mikhalych buys babies from drunks and hobos. Posing as [[StrugglingSingleMother struggling single mothers]], the beggars are sent into the streets with the babies in their arms. Mikhalych forces them to keep the children on drugs to make sure they stay quiet. With the drugs and without proper childcare, the infants frequently [[WouldHurtAChild die]], with at least eighteen bodies found by the [=FES=] in a mass grave. Even after his arrest, Mikhalych feels [[LackOfEmpathy no remorse]], showing that he views the babies and his adult subordinates as nothing but assets in [[{{Greed}} making money]].
* FandomSpecificPlot:
** There are a few fanfics, describing Tikhonov as a long-lost (abandoned or kidnapped) son of Rogozina.
** There are many Danilov/Vlasova fanfics, describing their relationship as Rita seeing Stepan as good stepfather for her son (since Danilov is canonically FriendToAllChildren).
* IdiosyncraticShipNaming: "Authority" (''Начальство'') for Rogozina/Kruglov.
* LauncherOfAThousandShips: Tatyana Belaya is a preferred character for shipping by fanfic writers (given that she is not a part of the aforementioned pairings). She is shipped with Tikhonov, Danilov, Kotov, Mayskiy, Belozerov...
* LikeYouWouldReallyDoIt:
** In "The [=FES=]'s Last Case", unknown attackers storm the building of the [=FES=], holding everyone inside it hostage. However, then the attackers [[spoiler:fatally shoot Amelina, Rogozina, and Selivanov]], at which point it becomes fairly obvious to anyone except first-time viewers that [[spoiler:either a miraculous cure will soon be administered or the shooting is staged]]. The latter turns out to be the truth: [[spoiler:it was all one huge BatmanGambit to get the murderer of this episode's victim to reveal himself]].
** "Novice" starts with Rogozina's announcement about her departure from FES. She presents new FES head, Yegor Shcheglov. But then Kholodov and Amelina find out that [[spoiler: Rogozina received 100 million rubles (roughly USD 1.5 million then) from Shcheglov]], so she basically [[spoiler: sold FES to him]]. At this point, there should be no doubt about her retirement being a part of some plan.
* MagnificentBastard:
** "The Dangerous Turn": [[TheDogBitesBack Inna Babayeva]] is a woman who plots the murder of her abusive, cheating ControlFreak of a husband. She devises a MakeItLookLikeAnAccident plan of sabotaging his airbag and then blinding him with a firework when his car is at a [[TitleDrop dangerous turn]]. To put the plan into motion, she hires their employee Fyodor, promising him half of her enormous inheritance and – in case he, against all odds, gets caught – the best lawyer available. She also tells Fyodor that, if he is found out, he should claim he did everything out of secret CourtlyLove for her. Fyodor's involvement is indeed eventually discovered by the [=FES=], he spins his romantic cover story and looks sympathetic, though he is still sent to prison to await trial. Babayeva, however, becomes free and wealthy overnight, and [[KarmaHoudini nobody has even an inkling of suspicion that she could be involved in the murder]].
** "Anatomy according to Glück": [[VigilanteMan Andrey Veresov]] is a student who decides to kill his OldFlame's sadistic husband, an anatomy professor. Taking advantage of the fact that his classmate decides to spike his group's food with a strong hallucinogenic drug but, being in love with him, warns him about it, Andrey waits for the drug to take effect during an anatomy test and slits the professor's throat while all the other students are high and therefore useless as witnesses. He hides his gloves in one of the internal organs preserved on display in the class and [[SelfPoisoningGambit eats a drugged pie himself]], establishing his own alibi. His gloves, the single definite clue against him, are found by the [=FES=] only thanks to a chance EurekaMoment, and after a momentary shock Andrey accepts his defeat with grace and calmly says he is ready to answer for the crime.
** "Diagnosis: Blonde": Alyona Karova plays the role of a vapid TrophyWife of a wealthy businessman to manipulate the FES squad members. Plotting to murder her husband, Alyona crafts a meticulous plan while keeping the agents in the dark, even manipulating Danilov to her benefit during their investigation.
** "The Man-Legend": [[BestServedCold Nadezhda Somova]] is a woman bent on killing Alexander Varshavsky who left her sister pregnant after a brief affair and refused to acknowledge his son after the sister [[DeathByChildbirth died in childbirth]]. Inspired by a news report about a serial burglar, Nadezhda has her husband Kirill kill Varshavsky, imitating the burglar's style. To enhance the deception, Nadezhda and Kirill stage their own burglaries and give the [=FES=] the criminal's description from the news report. The plot is revealed since the description turns out to be fake, but Nadezhda remains [[GracefulLoser calm and collected]] after her arrest and regrets nothing, since her sister has been avenged and her little nephew will inherit his father's wealth.
** "The Last Asylum": [[NeverMessWithGranny Irina Arsenyeva]] is a seventy-six-year-old [[HandicappedBadass handicapped]] retirement home resident who is [[UndyingLoyalty eternally grateful]] to nurse Lyudmila Pozdnyakova after the latter saved her life. When the new director Dubravin starts harassing Lyudmila and asks the worst-tempered patient Kopylov to purposefully make her job unbearable, so that Lyudmila would be left with the choice of [[SexualExtortion accepting Dubravin or quitting]], Irina decides to make Lyudmila's tormentors pay. Irina poisons Kopylov's vodka with crushed sedative pills, which results in a near-fatal poisoning of Kopylov and a fatal one of another patient, and frames Dubravin by leaving traces of his shoes and scattering the sedative powder in his office. Despite her age and failing health, Irina plans the crime so meticulously that the one nigh-imperceptible clue that points to her involvement is for a long time dismissed even by the [=FES=] as irrelevant. When Irina is found out, she [[GracefulLoser accepts defeat calmly]] and even gets disappointed she is allowed to stay under house arrest until trial, since [[SmallTownBoredom getting jailed would have brought a refreshing change]].
* MemeticMutation: Cities of Dobinsk, Gotymsk and Malinovsk seem to be Russian twin cities of [[Series/MidsomerMurders Midsomer County]].
* NauseaFuel: Body of the first victim in "Honey Trap" is reduced to a skeleton with remains of flesh on bones, so it certainly qualifies.
* NeverLiveItDown: "Птичка" ("Birdie"), Mayskiy's nickname for Belaya, is used by him ''once'' but has become a popular FanNickname for her.
* ReplacementScrappy: Olga Dunaeva and Veronika Zhilina. They both replaced at some point fan-favourite Margarita Vlasova and are viewed by most fans as weak substitutes for her.
* UnintentionallyUnsympathetic:
** In the final scene of "Medicine Against Wrinkles", Amelina smears Tikhonov's nose with the anti-age cream when he wants to go drinking with Lisitsyn, which is treated as lighthearted teasing. However, [[spoiler:the cream contains a poison which gets activated and causes death or at best a prolonged coma after coming in contact with alcohol, and only leaves the body after seven days]]. That means that Tikhonov has to abstain from alcohol for a week — but also has the horrifying implication that if he accidentally or unwittingly consumes alcohol (for example, in pastries), he will likewise [[spoiler:become comatose or worse]]. He would have been perfectly within his rights to charge Amelina [[spoiler:with attempted murder]].
** "In the Icy Reflection" ends with Vlasova telling Christina [[spoiler:(16-years old girlfriend of the killed choreographist)]] that he was just using her for sex. While many fans wrote off those words as Rita's typical GoodIsNotNice behaviour, some thought it was not the best time to say such things to a mourning girl, [[spoiler:(since Christina actually loved him).]]
----