After a few minutes, all the remaining ballistae on the first line of defense had been fired and then destroyed. Shortly after we retreated back about 100 yards to the next defensive line. The second defensive line consisted of five steam cannons armed with grapeshot, one armed with a large shell for a particularly tough target, and another fifteen ballistae. Between the first line and the second line were more barricades and hidden pitfalls. Given that many of the hidden pitfalls on the first line had already been collapsed, it made sense for us to retreat early to re-bolster our defenses.

Most of the rowboats had already dropped off their soldiers and were returning to their ships to pick up another round of soldiers. Some soldiers had been dropped off in the rough terrain further away from the beach, and were beginning to form their own groups. Most of that terrain, in addition to being very rocky and difficult to walk in, had also been booby trapped, so they should experience an even harder time navigating from the rocky portions to anywhere safe.

The first landing group from the smaller ships had about 250 soldiers, now we're facing more than four times that, which means we're very likely to be overrun as the battle progresses. That said, our entire goal of this defense has been to simply exhaust as many enemy soldiers as we can while losing as few of our own troops as possible. Outside of an enemy retreat, we were never expecting to actually win at this point in the island's defense.

With that in mind, we continue using our ballistae to slowly take down individuals at a distance. This time though, it seems they are more prepared with a proper plan. While some more heavily armored individuals move forward, individuals in the back are beginning to dismantle the defenses and barricades meant to slow them down. As for the armored individuals, there are a few who are leading the way who have large shields which are holding up to direct fire from the ballistae.

Thankfully, our defensive line is fairly spread out, which means we can still shoot from the sides, allowing us to still take some of them down. The first major issue came as one of them proceeded to barrel through one of our barricades. Given the size of their tower shield and heavy armor, I'm assuming they used some kind of magic to empower themselves. Thankfully, we still had the steam cannon with the single large shell in it. They might have heavy armor and a large shield, but even that couldn't hold up to a direct shot from a cannon. The shield and the man had a hole blown through his center, and he crumpled.

For ten minutes, this battle went on. We'd pick off individuals with our ballistae, and occasionally a shot would go out from one of the steam cannons, cutting down a handful of individuals. We suffered our first casualty as a particularly powerful individual sprinted and magically leapt forward through a lot of our defenses, and when they finally arrived at where a goblin was, they threw a knife fast enough that I assume it too was magically empowered, killing the goblin before anyone else could react. I was near enough to get to him before he moved on to another target, and although a knife was aimed at my neck, it grazed my shoulder as I dodged before impaling him from below with an earth spike.

As the threat from their army grew, I called for the next retreat. We'd used all our steam cannons on that row and many of the barricades and pitfalls had been destroyed or triggered, so staying at that line was going to get more hazardous. In addition, many of the rowboats have made it back to their ships, so the enemy is going to be getting reinforcements soon.

Our last defensive line on the beach consists of eight steam cannons, two of which are loaded with large single shells, another twenty ballistae on the ground, and the fort, which has fifty individuals inside it and fifteen ballistae on the wall facing the beach. The fort also features a moat and has burning oil ready to be poured over the gate if anyone dares to step too close.

Behind this last line there are still more pitfall traps, and after almost a half of a mile there is a small defensive position designed to help us retreat the remainder of our non-fort forces once it becomes clear that we've lost the beach. As of right now though, we've killed nearly five-hundred invaders, and I expect we'll be able to get at least another five-hundred before we call the retreat.

As the fight drags on, thanks to the proximity to the fort itself, we're having an easier time defending ourselves from the invaders initially. Unfortunately, as the minutes drag on, it gets more and more difficult as the previous defenses are dismantled, and a new, fresh batch of soldiers begin landing on the beach. I've also noticed that some of the soldiers who had abandoned their sinking ships have started to arrive on shore now. They're unarmored, so some of the ballistae in the fort take long range shots at them, and a few get hit.

This last line of defense holds better than the first two, but not by that much more. We're able to take out about three hundred soldiers before it becomes obvious that those of us not in the fort are in danger if we stay much longer, so I give the order to disable the ballistae, and carry the remainder of our ballistae ammo with us on our retreat. From here on out, it's basically up to the fort to deal as much damage as it can. The enemy would be foolish to attempt to chase us while we retreat, as they'd be exposing their backs to the fort's elevated ballistae attacks, so we are able to retreat without suffering any extra losses.

From our next defensive position, I begin organizing the next part of our strategy. The injured are to take the carefully plotted route between defensive positions all the way back to the city. It's unlikely they'll get ambushed, given our own defenses are designed around ambushes scattered about on the island. The majority of the rest of the fighters are to form three-man-squads and take up ambush positions around the beach that we've prepared. The goal of these spots is to prevent the enemy from scouting and expanding their influence beyond the beach for the next few days.

We want to make them feel like they need to build up their forces and properly organize before they can leave. Eventually, they'll overrun the fort, and likely turn it into their own defensive position. If we ambush them any time they leave the beach, they'll likely want to have a safe location on land to use for treating their wounded, and that fort would be the best bet for them. Which is exactly what we're hoping for.

We've purposefully made the fort in such a way that they'll find it useful for a force their size. Sure, it's useful for our fifty or so troops inside it, but we've sized the fort for nearly three times as many active personnel, with plenty of space for stockpiling supplies and keeping troops. We're even sacrificing those fifty troops to make sure that the enemy doesn't suspect anything.

I had a bit of an idea after remembering how Konkur described how the dwarven version of tectonic sense works. For them, they just detect when there is a change in material, and maybe a little information about the material. The floor of the fort is a few inches of stone. Under that would normally be sand, given where it's located. If you used a tectonic sense like ability, it'd even appear to be sand, even if you were really skilled at using it. It's a grainy material after all.

It's powdered sulfur though. Under that, in the center, is gunpowder. All the remaining gunpowder that we had, after we'd run out of time to machine it into any other usable ammo. Under that is more stone and a fuse leading to a buried tunnel. The explosion won't be that big, as there is at most a ton of gunpowder. What it will do though is blast the floor and throw about ten tons of finely powdered sulfur up into the air. When we know what's about to happen, we're going to prepare a burning ballista shot to fly into the powder cloud if it doesn't ignite on it's own.

That'll cause a deflagration, burning most of the oxygen in the nearby area, and replacing it with sulfur dioxide gas, which is heavier than air, which will settle back into the fort, and flow outward over the beach area. I'm not sure the exact concentrations that will occur, but given the amount of sulfur we've prepared, it should be pretty bad. Sulfur dioxide gas is toxic in high concentrations and an extremely potent irritant in lower concentrations. Many individuals suffer severe breathing issues for weeks when exposed to high concentrations of the gas.

This is technically chemical warfare, but I'm not aware of any Geneva conventions here. In fact, way before modern warfare, burning sulfur would sometimes be lobbed into fortresses during sieges to irritate the defenders. Likewise, tunnels that were being dug into forts would sometimes be flooded with sulfur dioxide to kill the tunnel diggers. It's not the most potent of toxic gases, and most individuals survive exposure to it, if they don't suffocate or breathe it for hours and hours on end.

We're not using it to directly kill though. We're using it to weaken their forces further. They won't have weeks to wait and recover in order to fight. Their supplies are already probably thinner than they'd like thanks to us sinking their ships. I can't discount healing magic potentially speeding their recovery, but if everyone is experiencing symptoms, it'd still take quite some time to properly heal their entire army.

We've already moved all our bargas up to the cave area, where they're likely moved inside by now. We've also culled a significant portion of the ground birds on the island on purpose. This army is going to be fighting with what food they have on them. So are we, except we've hidden our food caches, and made sure that every location we're fighting in only has enough for a few days of our own forces.

In the next few hours, the fort is going to fall, and then we'll patiently wait and watch through the night from a safe distance with the telescope, watching and waiting for them to unload more of their troops and supplies. If they decide to use the fort themselves, it'll prove extremely beneficial for us.