Chapter 15: A Reason to Fight, Part 1 is the first part of the fifteenth chapter in Valkyria Chronicles 4. The first combat mission in this is Versus Ausbruch.
Let's review the mission info, shall we?
"Captain Wallace will sortie from the ship to engage the enemy on the Crystal Sea. Our target is the enemy commander's tank. Unfortunately, the explosion of the Cavalier is causing the ice shelf to start breaking. Cracked ice may seem like sure footing, but another explosion could destroy it. And judging from out previous encounters, the Valkyria shouldn't be too far off. Their strategies are bound to be different from the last encounter. Be careful."
Location: Breaking Ice Shelf
Description: Defeat the Vulcan and avoid the Valkyria. Crymaria cannot be defeated, and cracked ice can be destroyed by explosive blasts.
"It won't be easy, but I have faith in you. Commence operations."