graph TD A[Start] --> B[Receive MP4 URL] B --> C[Validate URL Format] C --> D{URL Valid?} D -- No --> E[Return Error] E --> Z[End] D -- Yes --> F[Call Skill #207] F --> G{Transcription Successful?} G -- No --> H[Return Error] H --> Z G -- Yes --> I[Format Transcription] I --> J[Return Timestamped Transcription] J --> Z