The “Secret Conversation” feature is for a private and secure conversation with your friend using end-to-end encryption; Facebook will not have access to it. It’s currently only available via the Messenger app for mobile devices. To start a secret conversation: 1. From your mobile device, launch the Messenger app. 2. Locate a previous message for a contact you wish to enter into a secret conversation with or carry out a search for them. 3. Click on their name to bring up their profile. 4. Select “Go to Secret Conversation.” 5. In the “Secret Conversation” window, next to the left side of the text field, click on the time icon to set the time for the message to disappear after it’s read. 6. Then send messages as you normally would.