Secret Laboratory

0:00 The Secret Laboratory is the fifth dungeon of Persona 4 Golden, where the team rescues Naoto Shirogane: it can be entered from Sep 16, must be cleared by Oct 5, and descends from the entrance to B9F, where Shadow Naoto waits, per TheGamer. The way down is a key-card loop between B6F and B4F, through the Dominating Machine midboss. Shadow Naoto is weak only to electric, and TheGamer suggests level 50 to 55 for her. Persona 4 Revival keeps the dungeons' corridor format in its pre-release build, but Atlus has not shown the lab or said what changes in it as of Nov 3, 2026. The clip is BuffMaister's fight in Persona 4 Golden on PC at Very Hard.

Quick facts

Sources: TheGamer's Secret Laboratory walkthrough, Jan 31, 2023; TheGamer's Shadow Naoto guide, Feb 15, 2023.

Walkthrough

The lab goes down instead of up. TheGamer's order (TheGamer):

1. Down to B6F. Open the chests on B6F to find the Research Card.
2. Back to B4F. The Research Card opens the locked door on B4F, behind which the Dominating Machine waits. Beat it for the Leader Card. TheGamer's walkthrough puts this fight on B4F while its own affinity table lists B8F.
3. B6F again. The Leader Card opens the locked B6F door.
4. Down to B9F: Shadow Naoto. TheGamer suggests grinding to about level 55 first.

TheGamer's party guide brings Kanji, Yukiko and Yosuke, covering physical, electric, wind, fire and healing, with the protagonist on ice, light and dark.

How do you beat Shadow Naoto?

5:14 In Persona 4 Golden Shadow Naoto is weak only to electric, taking 125% damage from it; she resists fire and nulls light and dark. Her list is long: the single and party-wide -dyne spells of all four elements, Brave Blade, Mind Charge, Heat Riser, Debilitate, Tetrakarn, Makarakarn, Dekunda and Dekaja, and three skills to plan around: The clip is BuffMaister's fight in Persona 4 Golden on PC at Very Hard.

• Galgalim Eyes drops a party member's HP to 1 and may enervate them.
• Mute Ray drains HP and SP and may silence. Reflect it with a Magic Mirror or Makarakarn.
• Element Zero cancels the party's elemental resistances, so keep a healer ready after it.

TheGamer's party: Kanji as the main damage dealer, Yosuke or Chie in their second Personas (Susano-o, Suzuka Gongen), and Personas without elemental weaknesses on the protagonist, such as Tam Lin at level 53. Yukiko learns Amrita at her Social Link rank 6; Teddie learns it at level 61 (TheGamer).

Optional boss: Extreme Vessel

After the lab is cleared, the Extreme Vessel appears on B9F (TheGamer). No editorial guide read for this page gives its level or affinities. See Optional Bosses.

The Secret Laboratory in Persona 4 Revival

Atlus has not shown the lab as of Nov 3, 2026. Naoto's Revival character trailer came out during Xbox's Tokyo Game Show 2026 stream on Sep 17, 2026 (RPG Site). Revival keeps the original's procedurally generated corridors in the build PC Gamer played (PC Gamer, Sep 2, 2026). More on Naoto Shirogane and Naoto Social Link.

Frequently asked questions

What is the Secret Laboratory deadline in Persona 4 Golden? Oct 5. The lab opens on Sep 16.

What level should you be for Shadow Naoto in Persona 4 Golden? Level 50 to 55, per TheGamer, which suggests grinding to about 55 before B9F.

What is Shadow Naoto weak to? Electric, which deals 125% damage in Persona 4 Golden. She resists fire and nulls light and dark.

Where is the Research Card in the Secret Laboratory? In the chests on B6F of Persona 4 Golden's lab. It opens the B4F door to the Dominating Machine, which drops the Leader Card for the B6F door.

How do you counter Mute Ray and Element Zero? Reflect Mute Ray with a Magic Mirror or Makarakarn, and heal right after Element Zero, since it removes the party's resistances, per TheGamer's Persona 4 Golden guide.

Sources

• Persona 4 Golden: Secret Laboratory Walkthrough, TheGamer, Jan 31, 2023
• Persona 4 Golden: How To Defeat Shadow Naoto, TheGamer, Feb 15, 2023
• Persona 4 Golden: Best Party For Every Dungeon, TheGamer, updated Jul 18, 2026
• Persona 4 Revival showcases Naoto Shirogane in a new character trailer, RPG Site, Sep 17, 2026
• Persona 4 Revival feels just as good as its predecessor did 16 years ago, PC Gamer, Sep 2, 2026
• Persona 4 Golden - Boss Shadow Naoto [VERY HARD] [PC], BuffMaister, Jun 17, 2020 (video)