Order of Battle
After encountering Lambent Stalks and losing the Battle of the Emerald Spar Platform, the island of Vectes prepared itself for an invasion by polyps and stalks. Falling back on the tactics he'd used to win the Siege of Anvil Gate, Colonel Victor Hoffman prepared by having trenches dug and filled with Imulsion in order to lure in and incinerate the polyps that arrived. At the same time, a Raven carrying Delta Squad encountered a fleet of Stranded ships and worried that they were coming to attack Vectes. After setting up a meeting with Lyle Ollivar, head of the Lesser Islands Free Trade Association and successor to the late Darrel Jacques, Marcus Fenix learned they were aware of the Lambent threat and were simply coming to evacuate their people to leave the COG to its fate. After setting it up so that they could do that, Delta left. As they were preparing for the battle to come, the fleet arrived with more ships than expected and offered their help. In the end, instead of Lambent Stalks arriving, three Lambent Leviathans attacked with hundreds of polyps with two going after New Jacinto and the third going after Pelruan, which resulted in the Battle of Pelruan.
After hearing of the first attack on Pelruan, all forces were put on standby to wait for the first attack and finally one of the Leviathans arrived in New Jacinto's harbor. The ships CNV Fenmont and the CNV Vale of Dane attacked it with their guns, but failed to kill it and the Leviathan destroyed the Fenmont. After destroying the ship, the Leviathan rose up in front of the jetty Delta Squad and Hoffman was standing on and released hundreds of polyps before moving away. The Gears engaged the polyps for a time before running away with them chasing them while a second wave was apparently released onto the jetty. Delta Squad led the polyps into the imulsion-filled trenches and climbed out before the imulsion was ignited, incinerating hundreds of polyps. Not all of the polyps charged blindly into the trenches, so Dizzy Wallin led a bunch of other Assault Derrick drivers into using their rigs to bulldoze more into the trenches to kill those as well, as the rigs could withstand the polyp detonations. Heading back to the jetty to deal with even more polyps, Baird, Marcus, and Cole went through the Gorasni camp and found it under attack by polyps and defended by Stranded militia to their surprise and they join the fight. Originally, the polyps prove easy to defeat as they keep rushing en masse, but they eventually scatter and reform around the defenders and head into the camp as well. However, the Stranded had previously battled the polyps and half of them form an infantry line at the gate to the camp while the others split off into pairs. However, after a rifle jam caused a polyp to kill two of the Stranded, half of the rest charged the polyps. Eventually all of the polyps at the camp and on the shore were eliminated and the fight ended for a while as the Leviathans stopped their attack.
Break in battle and preparations
After the initial attack, there ended up being a break in battle of a few hours. Prescott and Hoffman took advantage of this break to evacuate all of the civilians inland and Hoffman convinced Prescott to go with them. Low on options, Hoffman decides to use the Hammer of Dawn to take out the Leviathans even though its extremely risky knowing that it would cause damage to the base, but the COG forces would otherwise burn through a lot of ammunition trying to defend themselves from the polyps. Shortly afterwards, the submarines Clement and Zephyr manage to get a lock on one of the Leviathans, but can't get the other one and believe it will take a simultaneous attack from both subs to take it out. At Pelruan, KR-239 manage to kill the Leviathan attacking there by unloading all of its ammo into its head while it was launching polyps. However, this Leviathan is smaller than the other two and there's no guarantee that trying that again will work. In order to figure out how to make his plan to use the Hammer work, Hoffman gathers Delta Squad, Trescu, and Ollivar to come up with ideas. Together they come up with the plan for some of them to take a patrol boat out and lure in the Leviathan so they can get a lock on it and kill it as far from shore as possible. As Anya Stroud is too busy fighting at Pelruan to actually input the coordinates and fire the laser, Corporal Damon Baird is assigned the task. The group contacts Captain Quentin Michaelson who prepares the Falconer for himself, Marcus Fenix, Dom Santiago, Augustus Cole, and Commander Trescu, who decides to go too. While Hoffman originally plans to join the crew, Fenix convinces him not to as the COG can't risk losing him. In order to better be able to hold the Leviathan in place, Michaelson makes a trade with the Stranded navy to get a harpoon with an explosive tip so they can harpoon it and hopefully hold it in place long enough for the Hammer strike.
After the Falconer got far enough out, the two subs opened fire together and destroyed the Leviathan that they had a lock on before quickly moving away so the other one couldn't get them. After the destruction of its friend, the remaining Leviathan surfaced to attack the nearest and noisiest thing: the Falconer, just like was planned. Once it surfaces, Marcus fires the harpoon into it, although the explosive in the tip didn't seem to injure it. The Leviathan started moving away while still attached to the boat via the harpoon and Marcus had the boat get close in order to get a good lock on it with the targeting laser he possessed. However, while a combination of the boat's winch and engines manages to slow the Leviathan down enough for Marcus to get the targeting laser on it, it was unable to stop it moving, making it hard to get a lock and the effort starts to burn out the Falconer's motors. Eventually the Leviathan makes what is believed to be a suicide run for New Jacinto, aiming for the carrier dock, and Marcus orders the pilot, CPO Frank Muller, to drag it to the west at the last minute. Falconer succeeds in pulling it away so that it will hit land to the west of the base and Baird gets as best a lock he can and, on Hoffman's orders, fires a six-second maximum setting blast from the Hammer of Dawn, successfully killing the Leviathan, but severely damaging New Jacinto as he was forced to fire the Hammer very close to shore, causing a landslide that takes out much of the cliff, although Falconer did survive the blast despite being close. However, the dead Leviathan beached and a couple of hundred more polyps were released from its carcass, but the defenders of the base successfully eliminated them with gunfire and flamethrowers and the battle finally ended.
At the same time as this battle was won, the defenders of Pelruan defeated the Lambent there as well and the threat finally ended. However, the Stranded decided that the COG were going to be destroyed by the Lambent and evacuated all of their forces from Vectes and ended the Stranded Insurgency. Ten days later, Bernadette Mataki found her missing dog Mac, but he was covered in fresh burns indicating that there were still polyps on the island and they didn't get them all. Minutes after finding this out, three Lambent Stalks popped up in the middle of the island and forces were scrambled to deal with them, hopefully before they released polyps, but showing that the Lambent threat to the island wsn't completely over.
- Gears of War: Anvil Gate pg 396