My Brother's Keeper

My Brother's Keeper is a hidden trophy/achievement in the Zombies mode map Der Eisendrache that appears in Call of Duty: Black Ops III. It is the main easter egg of the map, and it requires the player to "erase" the original "Tank" Dempsey. This also requires to continue on with Richtofen's plan, purging Group 935 and Groph, as well as blowing up Griffin Station and the Moon. Much like the Origins easter egg, it is entirely possible to complete this easter egg solo, with up to 4 players total though you can also do it with two or three players as well.

Step 1: Obtain the Ancient Bows
Every player must obtain and upgrade their Wrath of the Ancients to the Ancient Bows (Rune Prison, Wolf Howl, Storm, and Demon Gate).

Step 2: Shooting the Beacons
Go back to the tomb area and retrieve the original Wrath of the Ancients. Now, go to to the teleporter room and shoot each of the beacons/rods at the top of the teleporter. The player needs to shoot each one so that its end turns orange. Once the player lights them all up, the orange glow will disappear and the player will be able to move on to the next step.

Step 3: Shooting The Sparks
Around the map there will be random objects that could possibly be sparking. Only one object will be sparking at one time and the player will hear a cue (a Margwa growling) before it starts to spark. Shoot the sparking object with any upgraded Ancient bow and it will stop sparking. Shooting with anything else will result in an instant failure. The player will hear another cue and have to repeat this process three more times. Keep in mind that after the first try, the process will automatically start at the beginning of each next round until completed. After four sparking objects have been shot, the player will hear a different cue indicating they have completed this step. If the player takes too long or messes up, they will hear a failure cue which resets progress on the step and is unable to be resumed until the next round. Below are the locations of the certain sparking objects.

Possible Locations: Do note that if the player shoots at one of the possible locations while it's not sparking, it will also count as an immediate failure.
 * Car tire near Double Tap II
 * Phone near Quick Revive
 * Globe in small room besides Samantha's room
 * Phone on pillar near Power Switch
 * Clock in hall going from the clock tower
 * Box near work bench above Double Tap II
 * Radio in the adjacent corner from Speed Cola (the one close to the entrance)
 * Clock above fireplace in the Control Room

Step 4: Time Travel
Return to the teleporter and the bottom light will have turned purple. All players in the game must be in the teleporter in order to teleport.

Once the player teleports, they will now be in the same room but it will be cleaned up and obviously in the past. Here, the player cannot use their weapons or equipment. Dr. Groph will be here talking to Richtofen over radio and accessing his safe. Here the player must do three things before they are teleported back: If the player does not achieve all three goals above, they are able to repeat steps three and four every round. Note, however, that the symbols will change with each new round. Also after teleporting from the past, a Panzersoldat will appear, no matter what round the player/s teleported.
 * Hold the use button to pick up the glowing blue canister in the corner of the room near Dr. Groph.
 * Hold the use button to pick up the fuses to the right of the teleporter (left if the player is looking directly at the teleporter), on top of a box.
 * Remember the three symbols that appear on the vault (from top to bottom) after Dr. Groph locks it.

Step 5: Death Ray and Cracking the Code
During the same round the player is teleported into the past, interact with the Death Ray on the side facing away from the Clock Tower to add a fuse to the side, then go to the other side and pull the lever to switch the Death Ray from "Destroy" to "Protect". The Death Ray must be turned on at least once in the game in order to proceed with the next step.

Afterwards, head to the terminal near the Clock Tower and enter the three symbols from the safe the player memorized in order from top-to-bottom. This will open the safe across from the teleporter (the same safe seen in the past).

Step 6: Memory Simon Says
Head to the safe and interact with it to pick up the two fuses and the keycard. Insert each fuse into the Tesla Coils on either side of the Death Ray, then return the Death Ray to "Destroy" mode (no activation is required). Head to the terminals outside of the Clock Tower and interact with them. This activates a memory game of Simon Says.

The four symbols on the bottom screens will show for a couple of seconds before disappearing. Memorize the symbols' locations. The top screen will then show a symbol and the player must interact with the screen correlated to that symbol. Do this a number of times until the machine shuts down and the player hears an audio cue.

Repeat the game of Memory Simon Says at the terminals at the rocket launch site. If the player fails the game they can instantly restart the game by interacting with it again.

Note that if the player fails the game at the rocket launch site, they must restart the game back at the first location at the terminals outside the Clock Tower as well. Also, in co-op, Hellhounds will infinitely continue to spawn while a player is interacting with the terminals.

Step 7: Sabotage
The orbs atop the Tesla Coils will now be glowing. Interact with the green button on the back of the death ray to initiate the rocket crash. A rocket will appear in the sky and fly across until striking the bell tower (destroying the bell) and landing in the courtyard below. Dr. Groph will express his anger and lock down the cryogenically frozen "Tank" Dempsey with a lightning barrier, prohibiting the player from interacting with it. If they touch the chamber, they will be electrocuted.

Step 8: Purification and Return of the MPD
Look around the crash site, find the Vril Generator sitting in the snow, and pick it up. Afterwards, the player will need to teleport back in time again by shooting the sparks from step 3 (every round after the initial teleport will play a Margwa sound at the beginning signaling a spark has spawned) to find an item they could not access before.

Once in the past again, hold the use button on the book that is sat in a crate on the right side of the room. A case near the doorway will then open, revealing a stone tablet with the Keeper symbol etched into it. Pick it up with the use button and wait to teleport back.

Now, place the Vril Generator in the slot on the side of the tomb (in front of the location where the player obtained the Wrath of the Ancients) and a ghostly Keeper will rise out of the tomb. He will start traveling the map and stop at four separate locations. Note that when he stops by Double Tap II, the player will need to interact with the part of the wall to the right of the Keeper and under the lamp post to place the stone tablet. If this isn't done, the next part cannot be completed at this location.

Note: The player does not need every upgraded Ancient Bow in solo, only one is required.

A white circle will appear at the location the Keeper stops at. When you stand inside the circle, there will be a colored tint around the screen. The color of the tint correlates to the color of a specific Ancient Bow (e.g. an orange tint = the Fire Bow). The player needs to get kills with the indicated Ancient Bow whilst standing in the white circle. The more players that stand within the circle, the wider the circle's radius will become. Getting kills with the correct bow will transfer souls into the tablet, and once full, the ghost will move to the next location and repeat the process.

Note: If doing this solo, then the player can fill all four circles using the same bow.

After this is done four times, the ghostly Keeper will become solid (like they are seen in Shadows of Evil) and it will travel to the Undercroft. The Keeper will teleport to the Moon (indicated by it firing lasers in four directions), and after a brief audio cutscene, the Keeper will teleport the MPD from the Moon. One should notice that the MPD has blue canisters in each corner, except from one corner. Place the soul canister the player picked up earlier in the corner of the MPD that is empty, opening the MPD.

Once everyone is ready, each player must take their Ragnarok DG-4s and use the trap function on one of the blue squares used to activate no gravity. The player will then be teleported into a new room.

Step 9: Keeper Boss Battle
Here the player will meet a gigantic Keeper, the boss of this area. The boss fight has five phases, which differ from each other slightly.

Phase 1
The Keeper will currently have four attacks that mirror all four Ancient Bow abilities. The attacks are as follows: The fourth attack is important as it gives the player an opportunity to damage the Keeper boss. Before the shockwave is unleashed, the player will see a ball of electricity appear beneath the Keeper in the center of the room. As soon as the player sees this electric ball, a player will need to run inside of the electric ball and place down their Ragnarok DG-4 as a trap. The player should then run back away from the electric ball.
 * 1) A rain of skulls that come down from the sky. If a player is hit by a skull, they will be stunned, slowing them down a little bit. The player can shoot the skulls before they hit a player to destroy them.
 * 2) Spawning in skeletons (which act like zombies but with the model from Dead Ops Arcade 2: Cyber's Avengening).
 * 3) Summoning volcanoes that deal damage to the player (enough to down a player without Juggernog).
 * 4) A massive electric shockwave that instantly downs anyone who is touched by it. To avoid this shockwave, the player needs to stand behind one of the glowing blue pillars in the area.

Doing this correctly will plant the Keeper in the center of the room, and the rend on its chest will glow orange. The player now needs to shoot the rend to damage the Keeper. Once the rend ceases to glow, the boss can no longer be damaged.

The player needs to keep repeating this and, once it is done enough times, a Max Ammo will spawn in the center of the room. This indicates the start of Phase 2.

Phase 2
In this phase, the Keeper boss will disappear, and after a very short while, multiple Panzer Soldats will spawn around the room. For this phase, the player simply needs to keep killing the Panzer Soldats. Note that the first Panzer Soldat that is killed here will drop a Max Ammo upon death. Skeletons will continue to spawn in this phase.

Eventually, a Max Ammo will appear in the center of the room and the Keeper will begin speaking. He will reappear after a few seconds. This indicates the start of the next phase.

Phase 3
This phase is the exact same as Phase 1. The Keeper will now summon additional Hellhounds occasionally to attack the players. Repeat the same process as Phase 1.

Phase 4
This phase is just like Phase 2. It will consist of Panzer Soldats and Skeletons.

Phase 5
This phase is the same as the first and third. In co-op, a Panzer Soldat will also spawn in each time the Keeper is about to unleash its electric shockwave. Repeat the process as in Phases 1 and 3. Eventually, the Keeper will let out one final scream, then spin around, signaling its defeat.

Step 10: Sky Destruction
After defeating the Keeper, the player will be teleported back to the MPD. Here, Dr. Groph will express his extreme anger at the group and vows to destroy them and even going as far to state he will destroy the entire castle if he has to. On one side of the MPD, the player will see a glowing blue circle with a shape at the top of it that looks like the Vril Generator from earlier. Press the use button on the circle and the Summoning Key will appear. Pick it up after a few seconds.

Richtofen will explain that the player needs to charge the key in order to free the test subject. Take the key to the terminal next to the Clock Tower (the one used earlier for the Simon Says game) and interact with the terminal. The Key will float above the terminal and beginning spewing out electricity violently.

At this point, multiple rockets will be blasted at the Moon. This will cause the destruction of the Moon, killing Groph and any other Group 935 members at Griffin Station. A cutscene will then play.

Cutscene
The cutscene features the four characters (Richtofen, Dempsey, Takeo and Nikolai) walking up to the cryogenically-frozen original Dempsey, noting that he is still alive. At this point, Richtofen pulls out the Summoning Key and it begins to glow. This causes Dempsey, Takeo and Nikolai to float above the ground, out of their control. Richtofen says to them that the cryogenically-frozen Dempsey "will one day wreak havoc across the entire universe", and that he cannot be allowed to live. This makes Dempsey angry, and he begins to shout at Richtofen, stating they were supposed to "secure the package and be in and out clean", and that he shouldn't have trusted him. Richtofen then says that the Summoning Key will store the cryogenically-frozen Dempsey's soul, but that it can only be done after he dies. Richtofen then turns to kill the Dempsey inside the container, but Dempsey quickly shouts, saying that he should be the one to do it. Richtofen then releases Dempsey, and he walks up to the container, looking at his body inside. He mutters "good to see you, Tank" before switching off the container, killing the Dempsey inside. Richtofen then absorbs the now-dead Dempsey's soul into the Summoning Key.

Afterwards, all players are given all of the perks on the map (Quick Revive, Juggernog, Double Tap II, Speed Cola, Mule Kick, Electric Cherry, Widow's Wine, Stamin-Up and Deadshot Daiquiri) and are given a brief period of damage immunity. This will also cause the achievement/trophy to unlock for all players who completed the steps. It will also give a bonus 2500 XP and a Gateworm icon on the map selection screen.

Trivia

 * The title of the Easter egg is a reference to the story of Cain and Abel from the Bible. In the Bible, God asks Cain, "Where is Abel thy brother?", to which Cain replies, "I know not: am I my brother's keeper?"
 * The XP reward title upon completing the Easter Egg is "Frozen Freedom".