Telling Lies (stylized as telling l!es) is a narrative video game developed by Sam Barlow and Furious Bee and published by Annapurna Interactive in August 2019 for iOS, macOS, and Windows. Ports for Nintendo Switch, PlayStation 4, and Xbox One were released in April 2020. As with Barlow's previous title, Her Story, the game uses live action full-motion video of four people (played by Logan Marshall-Green, Alexandra Shipp, Kerry Bishé, and Angela Sarafyan) as part of video calls made between them, and the player will need to use tools provided from the game to piece together events and what statements may be lies to determine the overall mystery.

Barlow describes Telling Lies as a "desktop thriller" like Her Story, where the player becomes involved in a drama that is played out through stored video clips and other information presented on a virtual computer desktop. Telling Lies provides the player with numerous video segments that in the game's narrative, cover a two-year period and which have been stored on a stolen hard-drive taken from the National Security Agency. The player has the ability to search the hundreds of video segments on keywords as to piece together timelines, events, and interactions, all to try to understand why the four central people have been the subject of electronic surveillance, as well as the nature of the player-character's role in these events; this character appears female and can be seen in a virtual reflection of the in-game computer screen to the actual player. These clips only provide the video and audio from one side of the conversation, requiring the player to determine which clips may match the other participants, as well as potential interactions with around 30 other people. Players can scroll forwards and backwards within segments, highlight certain words in the video subtitles to use as search, and keep notes within an in-game memo pad. The player only has a limited amount of time within a single playthrough to scan material from the hard-drive, and would have to restart from scratch (losing all notes and bookmarks) if they want to see more. Barlow estimated that the content within Telling Lies is about four to five times longer than Her Story. There are three different endings that the player may reach through the game, depending on which character's videos they explored most frequently.

The game also contains a version of solitaire. The deck lacks the king of clubs and is therefore unwinnable.

In 2019, Karen Douglas, a former FBI agent, accesses a USB drive on her computer, watching the videos on it by searching them using keywords.

They tell the story of David Smith (Logan Marshall-Green), an FBI agent. During 2017 and 2018, David was undercover, supervised by his handler Mike, working on a case code-named Green Dagger. Its goal was to investigate potential acts of terrorism by the environmental group "Green Storm", led by the activist Riordan. To infiltrate this group, David would start by infiltrating a smaller team, the "Organizing Group", which targeted the corporation Prosperen, due to its plans to build a pipeline which the activists believed would pollute the water source. David approached one of the group's members, Ava (Alexandra Shipp), and developed a romantic relationship with her, eventually being invited to the Organizing Group.

The Organizing Group was led by 4 people: Eric, Wesley, Peter, and Simon. Simon was secretly a Black Kite agent providing information to the FBI, an arrangement David was unhappy with as he felt Simon was unprofessional. As David ingratiated himself with the group, he discovered that Peter had previously slept with Ava while she was underage, drugged her and filmed their relations. David attacks Peter, angering Ava and the FBI, and then uses a former contact named Harry to plant drugs on Peter, framing him. David grows increasingly unstable, and outs Simon as a Black Kite Spy. These actions and his growing closeness to Ava alarm Mike. David invites Riordan and the Organizing Group to a meeting on his boat, to discuss plans to disrupt movement on a key bridge vital for Prosperen's plans. While on the boat, Ava reveals that she is pregnant with David's child.

A new Black Kite spy infiltrates Green Storm, and David coordinates with him to trap Riordan into getting involved in a direct attack on the bridge. The plan goes awry, and David discovers that Mike and Black Kite have decided to hold off on Green Storm, and arrest the Organizing Group. David protests, but fails to persuade Mike, who tells him to end his infiltration. The Organizing Group is then arrested, including Ava. David is angry at Mike, but Mike notes that David had been withholding information, including Ava's pregnancy. David tries to continue meeting with the Organizing Group, but Karen Douglas, his then-field supervisor, bursts in to provide him cover to leave. David is furious, but agrees to withdraw. Ava is heartbroken and outraged at David's disappearance.

Meanwhile, David has problems with his wife Emma (Kerry Bishé) and daughter Alba. While David was undercover, Emma’s mother Laura moved in. During David's mission, Laura developed dementia and died, despite medical care by Steven, an anaesthesiologist hired by the couple. In addition, it is revealed that when David was Emma's boyfriend, he killed Paul, Emma’s abusive ex-boyfriend, with Emma as an unwilling accomplice.