Underground Exploration – Depth 3 — Armored Core VI: Fires of Rubicon Guide

Your guide to Underground Exploration - Depth 3 in Armored Core VI: Fires of Rubicon. Learn objectives, walkthrough tips, and how to defeat AC IA-C01: EPHEMERA.

Alright, let's dive into "Underground Exploration - Depth 3." This mission kicks off right after you finish Depth 2, and it's a big one, taking place in the Watchpoint Alpha area. Your client here is the Arquebus Corporation, and they're offering AC Parts, Combat Logs, COAM, and Data Logs as rewards. The music will be a mix of "Watchpoint Alpha" and "Clockwork Hostility." ## In-game Information This mission takes place in Watchpoint Alpha - Depth 3. Your main objective is to destroy the target, which is the core of a subterranean facility reactor. You'll need to disable a laser barrier to do this. You'll get 270,000 COAM and a Battle Log for completing it, plus extra rewards based on how many enemies you take down. ### Objectives Here's the rundown of what you need to accomplish: 1. Infiltrate the core of the Depth 3 reactor. 2. Destroy the pressure chamber. 3. Escape from the reactor core. 4. Destroy the autonomous defense AC, EPHEMERA. 5. Escape from the reactor core again. ## Walkthrough You'll start in the same chamber where you fought the AAP03: ENFORCER at the end of Depth 2. As you move into Depth 3, you'll see a huge chasm with a reactor powering a powerful laser barrier and the Enforcement System. The reactor itself is circular, surrounded by ten laser sniper cannons – these are a major pain, so deal with them first! From your entry point, a waypoint will guide you to a platform below that offers some cover from the sniper fire. You can descend further from here and head right towards a large support beam. This beam gets you closer to the laser barrier and out of the cannons' sightlines. Look around this area for the "Observation Data: The Enforcement System" data log. Now, you have a choice: you can head straight for the reactor and find a way inside, or you can try to get to the top of the reactor's exterior from the blind spot of the laser cannons and start taking them out from above. If you decide to go around the reactor's exterior, moving clockwise from where you entered Depth 3: * The first support beam you pass will have wreckage at the end containing the "Text Data: Professor Nagai's Log (5)" data log. Be careful, though, as two AM02: DENOISER MTs are guarding it. * The second support beam doesn't have anything particularly important. * The third support beam has a heavier variant of the DENOISER, marked by the LOGHUNT program. This one is guarding the IA-C01: EPHEMERA AC part. Grab it if you can! * The fourth support beam also has another heavy DENOISER marked by LOGHUNT. * The fifth support beam offers a bridge back towards the initial structures, giving you cover from the cannons. On top of the structure along the chasm wall, you'll find the IA-C01F: OCELLUS AC part, surrounded by several AM01: REPAIRER machines. * The sixth support beam leads you back to where you first entered Depth 3. Once you're ready, follow the waypoint to the reactor's entrance, which is a door near the bottom. Inside, be prepared for an ambush! Three DENOISERS will be waiting – one above and two below. The next room has another three DENOISERS, with one being a heavy variant. The third room inside the reactor is where you'll find the pressure chamber you need to destroy to bring the whole facility down. ### AC IA-C01: EPHEMERA After you destroy the pressure chamber, head back to the center room. You'll be locked in, and it's time to face AC IA-C01: EPHEMERA. This is an AC from the Rubicon Research Institute, controlled by the Enforcement System, and it's determined to take you down with the reactor. You'll have a two-minute timer for this fight, so speed is key! EPHEMERA is equipped with two homing energy launchers, a IA-C01W1: NEBULA plasma rifle, and a light wave blade. It also uses two repair kits and will activate Terminal Armor once its AP is depleted. EPHEMERA is all about aggressive close-range combat. It'll constantly pressure you with its homing projectiles and plasma rifle, making it tough to dodge everything. Its light wave blade is its most dangerous weapon, capable of quickly building up your ACS damage and punishing overloads. To beat EPHEMERA, you'll need to out-damage it. Bring high-damage and high-impact weapons. Many of its attacks can be tanked or dodged by strafing, but you'll need to quickboost to evade its regular wave blade swings. For its charged sweep attack, jumping over it is your best bet. Defeating IA-C01: EPHEMERA earns you a gold log for LOGHUNT and unlocks its partitions for you to use.