[AI Detective Manga] Episode 36: How did the second hand, which jumps one second at a time, know the lie in the video? ~Deadbeat Second reveals the trap of the "stopped second"~

監修者 Commit Ginza
20:14:15 / PROGRAM OUTPUT
The second hand is moving. The clock in the video is still on its pedestal.
But when the black transport hood was lifted, the pedestal was empty.
Kenji
Did the clock take an early remote leave?

It still appears in the video.
Appraiser
It's not even considered present.
First, let's examine one second of the video.
黒い搬送フードの下で空になった時計台座と映像モニターを調べる鑑定士と賢治
CASE FILE 36: Twelve Copied Seconds
  • Setting: Promotional shoot for a new watch at a luxury hotel
  • Missing item: Mechanical watch with dead-beat seconds, valued at 80 million yen
  • Shoot time: Automated shooting from 8:14:08 PM to 8:14:20 PM
  • At the end, a black light-blocking transport hood covered the pedestal and it was moved to the security area.
  • The watch was visible in the PGM video until just before the hood fully descended.
  • However, when the hood was lifted at the destination, the pedestal was empty.

① "Present" in the video, "Absent" on site. The watch is too clever.

From just before the shoot until discovery
20:00:00 Watch set to master clock; condition and serial number recorded.
20:13:08 Automated shooting and transport hood rehearsal conducted. Video ended at 11 seconds due to a save error.
20:14:08 Main shoot begins. Staff exited the booth to prevent reflections.
20:14:20 Transport hood completely covers the pedestal.
20:16:00 Unpacked in the security area; watch confirmed missing.
Kenji
The PGM video never went dark.
The camera worked diligently this time.
Appraiser
A bright screen is not the same as live footage.
時計撮影ブースと搬送フードの本番時系列を大型モニターで確認する鑑定士と賢治

② Kenji attempts to interrogate the battery.

Kenji
The second hand ticks, ticks, ticking along.

It's a quartz! Let's interrogate the battery first!
Appraiser
It's mechanical.
The interrogation will begin with you, Kenji, for jumping to conclusions.
This time's first suspect: The battery. Notably, not present in the watch on site.
電池を調べようとする賢治を制止し機械式時計だと説明する鑑定士

③ Three suspects. All suspicious despite just doing their jobs.

Suspect A: Emi Aizawa 32 years old, Product Stylist Prepared the pedestal and transport hood. Denied, preemptively for some reason, "I haven't added any features for the watch to escape."
Suspect B: Toru Otsuka 45 years old, Lighting Technician Darkened the area to eliminate reflections. Testified, "I only darkened the lighting, not the atmosphere on site."
Suspect C: Naoto Mamiya 39 years old, Video Director Managed PGM video and switcher. Claimed, "The video was never cut. Video doesn't lie."
Kenji
"Video doesn't lie."...
In a mystery drama, that's suspicious enough for a commercial break.
Appraiser
There will be no commercial break. Look at the evidence.
商品スタイリストと照明技師と映像ディレクターの三人を調べる鑑定士と賢治

④ At 0.25x speed, everyone seems like a culprit.

Kenji
With slow motion playback, I can see into the culprits' hearts!
Kenji slowed the video to 0.25x speed. Aizawa slowly turned around. Otsuka slowly narrowed his eyes. Mamiya slowly put down his coffee. Everyone looked very suspicious.
Kenji
Everyone's a culprit!
Appraiser
The playback speed is just making them look bad.
収録映像を低速再生して三人全員を怪しむ賢治と冷静な鑑定士

⑤ Deadbeat seconds tick once per second, even in mechanical watches.

You can't determine "mechanical or quartz" by appearance alone.
Appearance Possible driving mechanism Note
Jumps every second Typical quartz / mechanical with dead-beat seconds One-second ticking alone doesn't prove it's battery-powered
Moves smoothly Typical mechanical / quartz with sweep seconds Smoothness alone doesn't prove it's mechanical
Appraiser
Dead-beat seconds is a mechanism in mechanical watches that advances the second hand one increment per second. In typical models, it clearly jumps 60 times a minute.

However, the implementation varies by model, and the jumping motion of the second hand itself does not guarantee high precision.
Kenji
An 80 million yen quartz cosplay...
Appraiser
Please stop that expression before someone gets angry.
デッドビートセコンドの機械式ムーブメントと一秒刻みの秒針を説明する鑑定士

⑥ Deadbeat Kenji stops in three seconds.

Kenji
If I moved every second, I might understand how the watch feels.

Deadbeat Kenji, commencing!
Kenji moved his whole body jerkily, one second at a time, and after advancing three marks on the floor, he bumped into the filming cart.
Appraiser
That's not a complex mechanism; it's simply inattention.
一秒ごとにカクカク歩いて撮影用ワゴンにぶつかる賢治と呆れる鑑定士

⑦ One mark lingered for 60 frames.

Checking 30fps PGM recording frame by frame
12 sec
approx. 30F
13 sec
approx. 30F
14 sec
approx. 30F
15 sec
60F
16 sec
approx. 30F
17 sec
approx. 30F
  • The time the second hand appeared at the 15-second mark extended to approximately two seconds.
  • The additional 30 frames perfectly matched the hands, reflections, and even tiny dust particles.
  • Subsequent video was delayed by one second compared to the PGM timecode.
Kenji
The watch overslept at 15 seconds!
Appraiser
It wasn't the watch that overslept.
It was the video that copied the same single frame 30 times.
秒針が一秒だけ長く止まるフレーム列を大型モニターで発見する鑑定士と賢治

⑧ Kenji tries to arrest the Wi-Fi this time.

Mamiya: "If it stopped for a second, it must have been a communication glitch. It has nothing to do with the watch, or me."
Kenji
Then the culprit is Wi-Fi.
Handcuff the router!
Appraiser
The PGM is recorded locally, so at least Wi-Fi is not involved.

However, even with signal interference, holding the previous frame can happen. Therefore, we won't conclude it's an edit based solely on these 30 frames; we'll cross-reference the operation logs with the original camera footage.
The second hand is the "entrance." Tampering is confirmed with the original footage.
  • In one-second ticking, it's normal for multiple frames to stay on the same mark.
  • Frame drops, variable frame rates, and re-encoding can also change the appearance.
  • This time, we're cross-referencing the native PGM, switcher logs, and the camera's ISO original footage.
  • The on-screen time display is added after source selection, so the time can advance even if the source material is old.
Wi-Fiルーターへ手錠を向ける賢治を止めながら映像原本を示す鑑定士

⑨ The video switcher remembered all the culprit's operations.

PGM Operation Log
20:14:07 CUE MACRO START / Pre-registered sequence started with Mamiya's personal authentication key
20:14:08 AUTO: MEDIA PLAYER 2 TAKE / Switched to rehearsal material from one minute prior
20:14:15 AUTO: FRAME HOLD +30F / One missing second added with a still image
20:14:20 AUTO: CAMERA 1 RETURN / Returned to live camera
Macro Registrant MAMIYA_N / Mamiya's personal authentication key
Camera ISO original footage before being sent to PGM
  • From 20:14:08 to 20:14:20, the main camera recorded continuously.
  • The rear service hatch opened, and a deep olive-colored sleeve reached out to the pedestal.
  • At 20:14:10, Mamiya's personal badge was used on the hatch's electronic lock.
  • Immediately after picking up the watch, Mamiya slipped something into the inside of his cuff.
Kenji
Video doesn't lie. But the person who chose a different video leaves a log.
Appraiser
You're suddenly saying something correct today.
スイッチャー操作ログと後部ハッチから伸びる袖が映ったカメラ原本を照合する二人

⑩ "This is a cheap quartz." - That excuse is the most dangerous one today.

Mamiya crossed his arms. His jacket sleeve shifted, and a silver watch ticked one second at a time.
Kenji
It's moving second by second...

I'm suspending my quartz judgment today.
Appraiser
That's a good decision.
That is the stolen dead-beat second watch.
Physical verification
  • Case number, subtle dial features, and strap holes recorded before the shoot all matched.
  • The unique movement number visible through the display back also matched.
  • This contradicts Mamiya's explanation of it being "my cheap quartz watch."
間宮の袖口から見えた盗難時計の裏蓋と個体番号を確認して指摘する鑑定士

⑪ The culprit is video director, Naoto Mamiya.

It wasn't the watch that stopped for a second. It was the footage Mamiya copied.

Appraiser: "The main shot used a macro angle centered on the large second display at the 6 o'clock position, with the hour and minute displays mostly out of frame. One minute earlier, the second hand would return to the same position. You streamed an 11-second rehearsal video, which showed the watch and transport hood, into the main shoot, and extended the missing one second with 30 still frames due to a save error. You took the watch from the rear hatch in the twelve seconds that the automatic cue macro switched the video."

Crime Reconstruction
  1. During a rehearsal one minute prior, the watch and transport hood were recorded, but only 11 seconds remained due to a save error.
  2. Before the main shoot, the playback of the rehearsal material was registered to the automatic cue macro.
  3. To fill the missing one second, a process to hold one frame at the 15-second mark for 30 frames was also registered.
  4. During the twelve seconds when the video played the old material, the watch was retrieved from the rear hatch.
  5. Immediately after the transport hood closed, the live camera returned.
  6. The stolen watch was put on his wrist to make it look like a "cheap quartz."
Mamiya: "I thought no one would notice one second. And since the second hand moves like a quartz, I thought no one would suspect me if I wore it on my wrist..."
Kenji
Please don't use my initial wrong answer in your crime plan.
Appraiser
It was wrong before it was even adopted.

After the incident, Kenji endlessly loops footage of "himself working."

In the break room. A short video of Kenji earnestly typing on a keyboard repeatedly played on his laptop. He was secretly eating pudding next to the screen.
Kenji
If I keep playing footage of myself working, breaks also count as work.
Appraiser
You're working in the video, but you have pudding on your mouth.
Kenji
My conscience operates at a low frame rate.
Appraiser
(He's just stopped.)
働く自分のループ映像を流しながらプリンを食べる賢治を見つける鑑定士

Conclusion: The second hand is the entry point for tampering, but the original footage and logs are the decisive factors.

Appraiser
The dead-beat second is a mechanism in mechanical watches that advances the second hand second by second. One cannot determine "quartz because it ticks once per second" or "mechanical because it moves smoothly" based solely on appearance.

In this case, the second hand lingering at the 15-second mark was an entry point to finding an anomaly. However, merely having many frames at the same mark is not enough to definitively conclude a stop or edit.

The 30 frames where reflections and dust perfectly matched, the native PGM recording, the switcher operation log, the camera's original ISO footage, the electronic lock history, and the specific watch found on Mamiya's wrist. By overlaying all of these, we confirmed the video substitution and the culprit.

The movement of the watch is a clue. What determines the culprit is the accumulation of independent evidence.
*This work is a fiction. The implementation method, vibration frequency, constant force mechanism, and presence/absence of stop/zero-reset mechanisms for dead-beat seconds (jumping seconds / seconde morte) vary by model. Also, the driving method of a watch, absolute time, or video tampering cannot be determined solely by the second hand in a video. In actual video analysis, native files, frame times, metadata, GOP, audio, equipment logs, known samples, etc., are comprehensively considered. The switcher operation names, automatic cue macros, and personal authentication log specifications in the story are fictional, and actual functions and recording contents vary depending on the equipment and system.
Key deduction points this time
  • Even mechanical watches can have second hands that jump second by second.
  • You cannot conclude it's quartz based solely on one-second ticking.
  • Video where the second hand lingers is a clue to editing, not a standalone decisive factor.
  • If using material from one minute prior, the second display can start at the same position.
  • By separately checking the PGM and original camera footage, the twelve substituted seconds become visible.
NEXT CASE
Episode 37: It's March 1st, so why does the watch show February 29th?
~The Annual Calendar Exposes the "February Manual Adjustment Problem"~
  • I remember the 30th and 31st, but February is a bit tricky.
  • Testimony: "I've never touched the date."
  • Kenji tries to install a calendar app on his watch.
Next time, the annual manual adjustment will shatter the alibi!
※The adjustment range and operation method of the calendar mechanism vary depending on the model.

監修者のプロフィール

コミット銀座のロゴ

コミット銀座

2015年の会社設立以来、"高く買い、安く売る"をモットーに、顧客第一主義を徹底。価格面におけるメリットのみならず、お客様が安心して買い物出来る環境づくり、お客様に最適な時計の提案も実現。
徐々にお客様からの信頼も得て、多くの顧客様を抱えることに成功。高い知識を要するヴィンテージロレックスや、パテックフィリップを始めとするハイエンド商材の取り扱いを得意とする、新進気鋭の高級腕時計専門店。

時事ニュースの新着記事

Tags: 時事ニュース