Episode 2b: Two Fates. Narration script

Landscape, 1920x1080, 99 s. Calm, unhurried delivery, one idea per sentence. Timecodes are the real ones in renders/two_fates_v2.mp4 (scripts/assemble_two_fates.py, times list). Pauses between lines are intentional; the pictures carry those beats. About 200 words, roughly 95 s of speech.

Current voice: Azure neural en-US-AndrewMultilingualNeural (warm, confident), rate -6 %, pitch -2 Hz, generated by scripts/make_narration.py with the free edge-tts package into narration/01.wav .. 15.wav. To change the voice: python scripts/make_narration.py en-GB-RyanNeural --force.

# Time Picture Line Clip
01 0:01 Black, then the whole envelope fades in An antibiotic is about to enter a bacterium. 3.0 s
02 0:05 Slow push toward the outer membrane Everything you will see is a real structure. The proteins come from crystallography. The motion comes from molecular dynamics. 8.1 s
03 0:13 Tour: outer membrane, porin, periplasm This is a Gram-negative cell. Two membranes, a thin wall in between, and only a few ways in. 6.8 s
04 0:21 Tour continues: enzyme, inner membrane, target Inside the periplasm, two things can be waiting for the drug: an enzyme that destroys it, or the target it came for. 9.0 s
05 0:30 Title card TWO FATES Same drug. Same door. Two fates. 3.1 s
06 0:33 Split screen appears; both columns identical On the left, a cell that carries a beta-lactamase. On the right, a cell that does not. Watch them together. 7.2 s
08 0:41 Both pass the porin Through the porin. Identical, frame for frame. 3.3 s
07 0:44 Drug drifts through the periplasm in both Ceftazidime. A third-generation cephalosporin. The same molecule on both sides. 6.1 s
09 0:51 Columns diverge (HERE THEY PART) And here they part. 0.9 s
10 0:52 Left: docking in TEM-1, ring opens. Right: PBP found On the left, the enzyme catches it first. On the right, there is no enzyme, and the drug finds the protein that is building the wall. 8.8 s
11 1:01 Right: wall stops, gap, bulge. Left: THE CELL CARRIES ON Wall synthesis stops. The wall opens. The membrane pushes through. 5.2 s
12 1:07 Half-speed replay: both rings open Now the same chemistry, twice. The beta-lactam ring opens. 4.9 s
13 1:12 RELEASED. HARMLESS. / LOCKED. FOR GOOD. In the enzyme, the broken drug is released. Harmless. On the target, it stays bound. The protein is locked. 8.1 s
14 1:20 Outro: lysis shot slowed, closing headlines One cell dies. The other never noticed. One enzyme made the difference. That is what resistance is. Not a stronger cell. One extra protein. 10.6 s
15 1:33 End card Next: how bacteria get that enzyme, and how they share it. 4.0 s

Lines 07 and 08 are played in swapped order (porin first), because the porin crossing comes before the drug is alone in the periplasm.

Recording notes

  • Record at 48 kHz, mono is fine; leave 2 s of room tone at the start for noise profiling.
  • Read each line as its own take; the assembler places lines by timecode, so timing does not need to be perfect.
  • Export one file per line as narration/NN.wav (01 to 15), or one continuous file plus this table; either works.
  • The music is ducked under speech automatically; no need to leave extra gaps for it.

Where to turn this into audio

Own voice (preferred for a personal channel): any phone voice memo app, or Audacity on the PC.

Text to speech, if you want a draft or decide not to record:

Tool Notes
ElevenLabs Most natural English; free tier covers this length; “Daniel” or “Brian” suit documentary tone
OpenAI TTS (tts-1-hd, voice “onyx” or “echo”) Very clean, API or playground; cheap
Microsoft Edge “Read aloud” / Azure Neural (en-US-AndrewNeural) Free in Edge; export via a recorder, or use the edge-tts Python package offline-free
Piper (local, open source) Runs on this PC without an account; quality a step below the cloud voices

If you go with TTS, give me the voice and I will generate the 15 clips with edge-tts or Piper directly from this table and drop them into the mix.