There are home invaders in the house. If you call the police, they might hear your voice. Or worse, they're in the same room you're in. How can you get help?
One way is to call emergency services on your cell phone but keep it on mute and say nothing. The police will hear the home invaders and send a squad car down.
This is that trope. When someone finds a way to secretly call for help despite the danger being right there in the area. It doesn't have to involve the phone, but could involve the internet, Morse code, saying something that tips off would-be rescuers while sounding innocuous to the captors, or any other means available. What makes the trope what it is, is that the emergency call for help was unplanned, and is somehow kept hidden from the captors.
Related to, but not the same as, Covert Distress Code, which refers to a pre-determined code meant to tip people off. This trope is more about improvising on the spot. Tactical Reminiscence may overlap.
- Skeets, Booster Gold's personal assistant, comes with a "silent scream" that can alert his master of anything attacking him. The Linear Man in the Superman story arc Time and Time Again uses that to his advantage to lure Booster Gold to Metropolis so that he could capture him.
- In the Crimson Avenger story in Detective Comics #27 (the same comic that introduced Batman), Crimson is captured by a gangster. He knocks the phone receiver off the hook, thereby connecting the phone to the switchboard (the story predates direct dialling). The operator overhears the crook's Evil Gloating followed by a gunshot and calls the police.
- In Fantastic Four #348, Mr Fantastic is secretly being held prisoner by a Skrull infiltrator disguised as Sue. As the leave the Baxter Building together, Reed tells his robotic assistant that he and his wife are going on a day trip and that she should tell that to his "friends in the Marines". The robot, knowing that Reed has no friends that are in the Marines, looks up the phrase, discovering its history as a Covert Distress Code and realises that Reed is in trouble.
- Wonder Woman:
- Wonder Woman (1942): While Diana is the master of covert Mental Radio calls for aid since her mild telepathy allows her to make such calls without a physical mental radio on hand Steve Trevor and Etta Candy are able to do so with the bulky things on at least three separate occasions, which is helped by the fact that they don't need to make any noise to make the calls and the devices are almost entirely unknown outside of Paradise Island so the villains have no clue what they are.
- Wonder Woman (2006): A woman tried to hide from her incredibly abusive former supervillain husband that she was calling for help by calling a Women's Shelter rather than the police which changes what she's being asked and how she can respond. He thinks she's calling the police and trying to disguise it anyway and she only survives his fury because Wonder Woman shows up and chucks him outside.
- In Air Force One, the President is already in the process of calling the White House when he is captured. With the phone in his pocket, he tells his captor that the plane would automatically dodge any incoming missiles - which the Vice President correctly identifies as "an order from your Commander-in-Chief" to fire at the plane.
- Cellular is entirely about this. A kidnap victim manages to repair a broken phone and uses it to try to reach the police without her captors knowing.
- One of agent John Kruger's last acts before losing consciousness is to text the "bug out" code to key witness Lee Cullen in Eraser. Kruger's boss Robert Deguerin drugged Kruger with the intent of extracting the whereabouts of Cullen because Deguerin is a double agent, working with the villains to silence Cullen before she can testify.
- The Multitasked Conversation in In the Line of Fire involves Horrigan secretly communicating to police snipers where they should shoot.
- A Sister: A woman who has been raped and then kidnapped by a man (implied to be an ex-boyfriend or -husband), pretends to call her sister who's babysitting. In fact she calls 911. As the phone call plays out the woman has to answer the operator's questions—what color is the car, has she been hurt, does he have a weapon, where are they going—without revealing to the man behind the wheel that she isn't talking to her sister.
- A variant in S Storm. When Lau goes over to rescue Ebby, he tells Luk he is on his way to meet his first love, which calls-back to how he told Luk in a dream he was in the shipyard with his first love. Similarly, he asks if men if they have forgotten their office location. The number turns out to be the code needed to track his car via GPS.
- In the episode "Cops and Robbers", Castle happens to be talking to Beckett on his cell phone as a bank robbery begins. He keeps it hidden long enough to alert the police, but is soon found out.
- In another episode, Ryan is working undercover as an Irish mobster when he is discovered and taken to a remote location to be murdered. He manages to dial his partner's number on one of his captors' cell phone and describe where he is being taken so that the cops are able to rescue him and capture the mobsters.
- In real life, emergency services are starting to enable texting to them; this is one of the reasons for doing so, along with hearing-impaired access.
- However, in a rather serious case of Television Is Trying to Kill Us, the UK police warn that a completely silent call from a mobile won't be enough to alert the police - you should tap on the handset or cough in order to make yourself heard if possible, or failing that (in the UK) press 55 when prompted to do so.
- Jeremiah Denton, an American POW captured in Vietnam and forced to make a video claiming the prisoners were being treated well, secretly blinked the word "torture" in Morse code to communicate that the words coming out of his mouth were a lie and get the word out of what was really going on.
- In 2015 a woman being held hostage by her abusive boyfriend persuaded him to let her order pizza using an online app. She wrote "911 Hostage" in the "comments" section of the order, and the pizza restaurant sent the police to her house to investigate.