Most AI models generate 5–10 second clips. Often that's not enough: the hero hasn't reached the door, the camera hasn't finished its orbit, the story isn't over. Extend Video shoots the continuation from exactly where the clip ended.
Upload a video up to 30 seconds — generated or filmed on a phone. Optionally describe what happens next: "he opens the door and steps outside". Choose how much to add: 5 or 10 seconds. MiniMax H3 Turbo continues from the last frame, keeping the subject, lighting, color and camera motion.
You get one seamless clip: the original plus the continuation. Extend it again to build a longer scene step by step.