Marguerite (greenhouse)

Chapter: 3 · Yard & Old House
Where: The Greenhouse and the Old House west wing: Old Kitchen, Old Corridor, Fertilizer Room, Old Bedroom, Old Living Room, Old Entrance Hall, Landing, Old Upstairs and Upper Level

Weak point

The head (+10%). The belly hive takes −20% until it bursts

It starts when you drop through the hole in the Potting Room (Greenhouse 2F) to 1F: you are locked in, and when you climb the back stairs Marguerite bursts through a window and grabs you. She has about 15,000 HP. Almost every guide says her weak point is the belly, but the datamine and a second independent tester agree: the head takes more damage and the belly hive takes less until it bursts. Expect about 17–24 M21 Shotgun shells to the head depending on your rank; cut that down with the 44 MAG and Enhanced Handgun Ammo. Fire barely dents her HP (Flame Rounds −60–80%, Neuro Rounds −70–90%, Burner burn −83%): the Burner is for her swarms and hives, and the grenade rounds are for Mutated Jack and the Fat Molded.

Reward

The Lantern, the counterweight for the Old House scale; a gate crumbles and lets you out. "Fly Swatter" achievement if you shoot her down mid-leap.

About 15,000 HP (single source; no guide gives a shot count to test it). A Flame Round is worth between half and two shotgun shells to the head: at most, use one to break a charge or a grab. Another valid plan: wait for her at a spot on 2F instead of chasing her (saves ammo, but she lays more hives). Madhouse: Circular Saw (ZL + ZR held) on the belly; she spends most of the fight running away.

Step by step

Before: with 9 Antique Coins you can take the 44 MAG from the trailer birdcage. The toilet Treasure Photo, under the Greenhouse stairs, leads to 44 MAG Ammo ×3 in the trailer's toilet. Save in the trailer before you drop: "Fly Swatter" is lost if you miss it.
Loot during the fight (Normal): Psychostimulants on the Old Corridor couch (take them to see the items); Shotgun Shells ×8 + Strong Chem Fluid in the spider locker of the Fertilizer Room (burn them off); Handgun Ammo ×15 + Burner Fuel ×75 on the Upper Level table; Burner Fuel ×75 by the ladder; 2 First Aid Meds, a Herb and Chem Fluid in the Greenhouse.
If she grabs you, attack to break free. She can pull you up from above or grab you from below through holes and cracks: shoot fast. Stay on 2F whenever you can.
Hunt her, don't hide: left alone she lays hives. If you hear groaning and bodily noises she is building one: shoot her to interrupt it. Finished hives can be burned or shot apart.
Knock her off walls and ceilings with the handgun and step back when she falls, because she thrashes. On her back she struggles to get up: that is the moment to empty the shotgun, the 44 MAG or Enhanced Handgun Ammo into her head.
Shoot the belly only when it is all you can see: even at −20% it does about three quarters of a headshot. If the hive bursts, it becomes a weak point.
Wall leap: she stops, looks at you and jumps. Shoot her in mid-air (the shotgun is best) for the "Fly Swatter" achievement. She only climbs 2–3 times per fight.
Reload whenever she retreats, and drop to 1F to break contact and heal.