Iron Nest Mission 12: Fire on Call - Solutions

Worked example: Bearing, range, charge and elevation figures below come from a sample playthrough. Enemy spawns and your Iron Nest’s position vary each run — always measure on the map and follow the in-game ballistic calculator.

Mission Critical Strategy: The Standoff Number

Fire on Call is the only mission in the campaign where your own side is the primary hazard. Every other mission measures success by what you destroy. This one measures it by what you don’t destroy — and the instrument that keeps you honest is a single number on the teleprinter.

Every support request in this mission arrives in the same format:

Friendly elements engaged, enemy position at grid X, friendly standoff Y metres.

That standoff figure is the whole mission. It tells you which shell in your locker is legal:

Standoff vs. shell	Verdict
Standoff larger than the shell’s blast radius	Safe — load H or HCHE and fire normally
Standoff smaller than the shell’s blast radius	Danger-close — H and HCHE are prohibited; load AP

The failure state is instant and unrecoverable. Many operators lose this mission not by missing, but by firing the right grid with the wrong shell.

Why AP is the danger-close answer

AP (Armor-Piercing) is normally thought of as an anti-armour round. In Fire on Call it earns its place for a different reason: it delivers its effect in a tight, localised area. Where H splashes across a wide radius and HCHE is wider still, AP concentrates everything into the point of impact.

For danger-close work that is exactly the property you want. The enemy position is destroyed; the friendly position a few dozen metres away is untouched.

The two shells that are always available to you

• SMK (Smoke) — for pinned infantry with no shootable target. It does not kill anything; it removes the enemy’s ability to see, which is what “pinned” actually means. Re-lay it as it dissipates.
• H (High Explosive) — reserved strictly for deep, unambiguously safe requests. If a request arrives from a target well behind the enemy line with a large standoff, H is efficient and you should not waste AP on it.

War Horn discipline

The War Horn is not a morale button. It is the signal that tells the infantry to begin their storm. Sequence matters absolutely:

Fire first → confirm impact → then sound the horn.

Sounding the horn before your shells have landed sends the friendlies forward into your own barrage. This is the second-most-common failure in the mission after the wrong-shell error.

Pre-Calculated Firing Solutions

Target	Target Grid	Turret Bearing	Target Range	Powder Charges	Elevation (θ)	Ammunition
House Block ALPHA — danger-close	Grid D2 6.4	068.0°	9.20 km	2 Charges	46.00°	AP (Precision)
Trench Line BRAVO — danger-close	Grid D4 1.9	074.5°	8.60 km	2 Charges	43.00°	AP (Precision)
Pinned Infantry — smoke screen	Grid D3 8.7	071.0°	9.60 km	2 Charges	48.00°	SMK
Rear Depot CHARLIE — safe, deep	Grid D9 2.2	082.0°	13.20 km	3 Charges	52.80°	H (High Explosive)

[!WARNING] The first three rows sit in the 5–10 km band (2 charges, multiplier 5.0). The rear depot crosses into the 10–15 km band and needs 3 charges. Mixing these up is the fastest way to waste a shell in this mission.

Step-by-Step Operator Routine

Phase 1: Requisition (Timer: Stopped)

1. Buy 6 AP shells — this mission is AP-heavy and running out mid-engagement costs you the objective — plus 3 SMK and 2 H.
2. Buy 20 powder charge bags. Requests arrive faster than you expect and you will not have time to re-stock between them.
3. Read the mission briefing and note which grid squares contain friendly units. Mark them on the map board with a distinct colour.

Phase 2: First Danger-Close Request

1. Request arrives: enemy at D2 6.4, standoff reported at short range.
2. Check the standoff before touching the ammunition locker. Short standoff → AP only.
3. Load Left Gun: 1 AP + 2 charge bags. Elevation 46.00°. Bearing 068.0°.
4. Fire. Confirm the enemy position is silenced.
5. Only now sound the War Horn to release the infantry storm.

Phase 3: Pinned Infantry — Smoke

1. The teleprinter reports friendlies pinned with no engageable target.
2. Load SMK with 2 charge bags, elevation 48.00°, bearing 071.0°.
3. Fire the screen and watch it establish. If the infantry are still pinned when it thins, re-fire the identical solution.
4. Do not attempt to suppress the pinning position with HE. You do not have a clean standoff figure for it.

Phase 4: Second Danger-Close Request

1. Request arrives: enemy at D4 1.9. Standoff again short.
2. Re-charge to 2 bags, re-lay to 43.00°, bearing 074.5°.
3. Fire AP. Confirm. Then sound the horn.

Phase 5: Safe Deep Request

1. A request arrives with a large standoff against a rear depot at 13.20 km.
2. This one is not danger-close. Load H, re-charge to 3 bags, elevation 52.80°, bearing 082.0°.
3. Fire and confirm. Save your remaining AP for any further close requests.

[!IMPORTANT] Operator Rule: Read the standoff number before you open the ammunition locker, not after. In Fire on Call the shell choice is the decision; the firing solution is just arithmetic.