Section one, the hunter becomes prey. April 24th, 1943, North Atlantic, 480 mi west of Ireland. The spray hits Commander Peter Gretton’s face like ice needles as HMS Duncan pitches forward into another wave. Salt crusts his eyebrows. His knuckles are white on the bridge rail below decks. The AIC operator’s voice crackles through the voice tube.

 Contact bearing 270. Range 1,200 yards, moving left to right. Gretan doesn’t smile. He’s been hunting Ubot for 3 years now. And he knows the status. Ticks by heart for every 10 depth charge attacks. Maybe one results in a kill. Maybe more often you’re throwing 300 lb of a ML into the black water and hoping praying the tea somewhere in that expanding sphere of destruction. Steel meets steel.

 The Ubot captains know it too. They’ve learned to dive deep, change course, rig for silent running. They wait out the attack, then surface hours later to continue their hunt. But today, HMS Duncan carries something different. Hedgehog crew standby. Gretan orders on the forward deck.

 24 spigot mortar point skyward in a circular arrangement. Each loaded with a 65lb projectile. They look absurd like someone bolted a collection of drain pipes to the deck. Royal Navy veterans call it the porcupine. Gretton has heard the whispers. Another bloody useless contraption from the buffins. The weapon’s been operational for a year and most captains don’t trust it.

 Why would they? I t throws projectiles ahead of the ship, not behind like depth charges. The mortar fire in a circular pattern that covers a 130 ft diameter and hears the part that makes season. Tubmarine warfare officers shake their heads. The projectiles only explode on contact. contact, not time delay, not depth setting contact.

 Which means if you miss, there’s no explosion, no massive d water detonation to rattle the Ubot’s hull. Destroy their hydrophones, throw their navigation off. Nothing. Just 24 duds settling into the Atlantic mud. Range 800 yd. The ASDIC operator calls holding steady bearing the Ubot below. They don’t know it yet, but it 911 under the command of Captain Lutinant Helmfi is following doctrine.

 Fi has survived 11 patrols. He knows the sound of a British destroyer screws knows the telltale ping of Astic sweeping for him. He’s ordered a dive to 600 ft. A hard turn to starboard. And now th air creeping at three knots, barely moving. In the control room, 38 men breathe shallow. automatic breaths. The only sounds are the creek of the pressure hole and the faint tick of the depth gauge. They’ve done this dance before.

The destroyer will pass overhead. Depth charges will fool those familiar rolling thunderclaps that shake your teeth but rarely kill. Then silence the end surfacing. Except this time is different. Range 500 yd. ASDIC reports. Bearing steady, Gretton plants his feet. Fire hedgehog. The forward deck erupts not with thunder but with a rapid thump thump thump thump as all 24 mortar fire in sequence over 3 seconds.

 The projectiles arc forward in a spread pattern reaching their apex then plunge toward the water to 150 yd ahead of Duncan’s bow. They enter almost silently 24 small splashes in the gray Atlantic. Then nothing. Four seconds. Five. Six. Bloody hell. Mutters the furs. T officer. Another me. The ocean erupts. Not one explosion. Seven.

 Seven contact fused warheads striking you 191’s pressure hole simultaneously. 735lb torp charges each 50% more power. UL and TNT detonating directly against riveted steel plating. The sound reaches the surface as a single crushing boom that sends a column of white water 60 ft into the air. Oil foe. Low seconds later. Black and spreading. Then debris.

A life jacket. Wooden planking. A boot. In E1 191’s control room, there is no time to scream. The forward torpedo room floods in 1.3 seconds. S. The pressure hole buckles inward with the force of 400 tons per square foot. Men die before their nervous systems can register pain. The submarine stone rises briefly as steel well breaching in reverse then slides beneath the waves as a 40° angle.

Helmet Fiend’s 11th patrol has lasted 19 days. It ends at 11:47 a.m. in 2,400 ft from a water drop dot on Duncan’s Bridge. Gree Tom watches the oil slick spread. His hands are steady now. He thinks about the statistics, then attacks for every kill with depth charges. This is his first time using Hedgehog operationally. First time.

First kill. He reaches for the voice tube. Well done, Hedgehog crew. Mark the location. Signal to Admiral T. Yubot destroyed by contact mortar. Position 5214. 2,231 ft W. What? Gretton doesn’t know. What can’t know yet is that in the next 28 months, weapons exactly like the one mounted on his forward deck will sink 46 more Ubot that German commanders will begin refusing patrol assignments in hedgehog heavy zones.

 that the weapon they’re mocking today will achieve a 25% hit rate five times better than depth charges. That Admiral Carl Dunits will write in his war diary. The enemy’s forwardthrowing weapon represents a fundamental shift in anti-ubmarine capability, but that’s 28 months away right now. Peter Gretton simply watches the oil slick and thinks maybe the buffins got one right.

 Section two, the problem that wouldn’t die. September 1940, Admiral T research laboratory, Teddington, England. Lieutenant Commander Charles Goodiff paces in front of a blackboard covered in equations. His audience six naval officers and three civilian scientists watches with the weary expressions of men who’ve sat through to many presentation s promising miracle weapons.

 Outside, London is burning. The Blitz has been going for 3 weeks. Every night, German bombers turn the sky orange. Every morning, new rubble fills the streets. But good isn’t thinking about the Blitz. He’s thinking about the Atlantic. Gentlemen, he says, tapping the blackboard with chalk dusty fingers. We are losing the convoy war.

No one. He disagrees. The numbers speak for themselves. In the last 6 months, Ubot have sent 274 merchant ships to the bottom 1.4 million tons of shipping, oil tankers, grain carriers, ammunition, transports. Britain is an island nation, and Germany is slowly strangling it. The Royal Navy has destroyers, corvettes, depth charges, all the tools of anti-ubmarine warfare, and they’re losing the problem. Good continues.

 is not the depth charge itself. It’s how we deploy it. He draws a simple diagram. A ship, a submarine below, depth charges falling behind the ship’s stern. When we detect a Ubot with steam directly toward it, our Asticure Solar gives us range and bearing. Beautiful, accurate. But here’s where it falls apart.

 He drive or a red X over the diagram. The moment we’re close enough to drop charges. We’ve passed over the target. We lose contact. The ASDIC can’t see directly beneath the ship. There’s a blind spot roughly 200 yd across. Commander Ralph Fischer, a veteran of 17 new kills, shifts in his seat. We’re aware of the dead zone.

 Lieutenant Commander, we compensate by setting the charges to our best estimate of your best guess. Good evenive interrupts. You’re guessing the Ubot’s depth. Guessing whether it turned left or right in those crucial seconds when you couldn’t see it, guessing its speed. And the Ubot commander knows this.

 He knows he has 20, maybe 30 seconds of invisibility. So he does exactly what you do. He changes everything. New depth, new heading, new speed. Good picks up a depth charge fuse from the table. These are set by timer. We drop a patent say 10 charges and hope one explodes close enough to crack the press. Your hole, but close enough means within 20 ft.

 20 ft, gentlemen. In an ocean that’s 2 mi deep and pitch black. The room is quiet except for the distant thud of anti-aircraft guns. The kill rate is 7%. Good says 7% for every 14 new boat attacks. We get one confirmed sinking. Meanwhile, they’re sinking four, five, six ships per patrol, he says. Dammer fuse, I’m proposing something different.

What if we throw the charges ahead of the ship? What if we maintain aic contact right up until the moment of impact? What if the weapons own? Why explode on contact? Guaranteeing that every explosion is a hit. The silence changes quality. Now they’re interested. Forward throwing, Fisher says slowly. Like a mortar. Exactly like a mortar.

 A ring of mortar on the for deck firing ahead in a pattern. 24 projectiles covering a 130 ft circle. The ASDIC operator keeps tracking. He never loses contact. He talks the captain onto target. At the last second, fire. The projectiles land ahead of the ship, ahead of the Ubot’s projected position. Contact fuses.

 No explosion unless you hit a scientist in the back. Dr. William Finch from the ordinance board raises a hand. The contact fuse is the impossible part. You’re talking about a projectile that survives a 40g launch, flies through the air, hits water at 70 mph, sinks to potentially 800 ft depth, then detonates reliably on contact with steel, but not on contact with water, seafloor, or a stray whale.

 Yes, good says that fuse dozen we invent it. Finch laughs a short bitter sound. Do you have any idea how many engineers have tried to create a reliable contact fuse for underwater ordinance? The Americans have been working on it for 3 years. The pressure variables alone. We don’t have 3 years. Dr. Finch, we have months, maybe weeks.

The room erupts in overlapping voices. Impossible. Two. Oh, complex. Never been done. Good. Lets them argue. Lets them exhaust their objections. Then he walks to the window and points toward the temps where smoke still rises from last night’s raid. Jen Tleman. His voice cuts through the noise. In the last month, you boat sank 63 ships.

That’s 350,000 tons of cargo. That’s food, fuel, ammunition, aircraft parts. That’s the raw mat. Aerials we need to keep fighting. At the current rate, Germany will force our surrender through attrition alone. No invasion necessary. He turns back to face them. So yes, the fuse is impossible. Yes, forward throwing mortar are complicated.

e

 Yes, we’ve never done this before. Build it anyway. Commander Fisher stance. You’ll need test vessels, ranges, ordinance facilities. I’ll need more than that. I need this project classified at the highest level. If the Germans get wide, we’re developing a forward throwing contact weapon. They’ll adapt their tactics before we deploy.

 What are you calling it? Good glances at his notes at the sketch of 24 mortar arranged in a circular pattern bristling from the deck-like quills. Department FV2 is developing several projects. Anti-submarine mortar, a head throwing weapons, multiple designations. He pauses, but the sailors will call it something else.

 They always do something descriptive. Fisher studies the DR wing. 24 spigots pointing skyward. Sharp, defensive, dangerous. Hedgehog, he says, though call it hedgehog. Good. If not, then hedgehog it is. 3 months later, the prototype exists. A wooden frame in a Teddington workshop holds 24 mortar arranged in four rows of six. The contact fuse has been tested 247 times, 183 failures, 64 successes.

 The success rate is climbing. Engineers work 18-hour shifts. Churchill himself has been briefed. The project coder name is fairway but everyone involved calls it by fisher’s name. Hedgehog in the north battle atal antic. Ubot are having their best month of the war. 95 ships sunk 500,000 tons. Admiral Carl Dunit calls it the happy time.

 But in Teddington in a workshop that smells of core diet and welding flux, Charles Goody watches a contact. Few successfully detonate on its 71st consecutive test.