Episode five of the single-shot ladder, and the one that stops you torching credits. Three tools that turn blind re-rolling into deliberate debugging. **Seeds.** A seed is the random starting number behind a generation; fix it and the same prompt plus the same settings reproduces the same clip. We cover the "lucky accident" tax (landing a great shot on a random seed you never captured), how seed fields show up in current tools, and the core workflow: **lock the seed, change exactly one variable, compare.** Plus the honest limits, seeds often don't survive a model-version bump, don't port across providers, and in image-to-video the start frame (episode 3) is the real reproducibility lever, not the seed. **Negative prompts.** Telling a model what to avoid often backfires, many video models (e.g. Runway Gen-4) read your words as what *should* happen, so "no clouds" can yield more clouds. The fix is positive phrasing: "a single person walking alone," "steady camera on a locked tripod." Tools with a dedicated negative field can help, but only for stability hints (no flicker, no drift), never vague quality words. **The failure modes,** named so you can recognize them: morphing hands, face distortion at distance, identity drift, broken physics, warping in fast motion, flicker, jelly/wobble, background instability, the plastic "AI sheen," gibberish text, and mushy small details. The organizing idea, **structural vs stylistic**: structural failures (physics, drift, coherence) need a *changed shot* (shorter, simpler, an image anchor, a different model), not a reworded prompt. Plus a triage loop, a worked convergence example, and the pitfall: burning 30 credits forcing an impossible shot instead of breaking it into achievable pieces. Callbacks to ep1 (cost-per-finished-clip), ep3 (start frame beats seed), ep4 (shorter duration kills failures). Forward to character consistency and conversational editing. *AI-generated podcast by OCDevel. Model behavior, seed reproducibility, and negative-prompt support move monthly; bench your own shot.*