Fighting Alongside Death

Fighting Alongside Death is a quest given to Byleth by Jeritza in Fire Emblem: Three Houses during the War Phase of the Crimson Flower Route. Unlike other quests the only participants are Byleth and Jeritza.

Quest Details
"Secret orders from the emperor. Do not keep me waiting."

Requirements
"Go into battle and subdue the enemy. This is a covert mission, so you'll be pairing with only Jeritza."

Quest-Giver Dialogue
"Secret orders from the emperor. You and I are to launch a surprise attack on the enemy base in the eastern part of Fódlan. Come."

Quest Completion Dialogue
"So, you saved the village from bandits. Now that we've had this learning experience, vigilante groups have popped up across the land. Hopefully this will help protect the peace."

Location
Given to you by a female soldier dressed as an archer near the back end of the Entrance Hall.

Rewards

 * Agarthium x1
 * Reaper Knights
 * 700 Renown

Strategy
Talk to the Jeritza at the entrance to the training grounds and accept the quest on the player's next day off.