The Paradox Begins

The Paradox Begins is an achievement featured in the Zombies map Los Shadows. It is the main easter egg of the map, requiring players to "enter the rift". It can be done either in solo or with multiple players.

Step 1: The Tesla Rods
Around the map are two different tesla rods, which can be picked up by the player and placed within two slots at the top of the memorial at the fountain. Continue playing the game until a round with thunder and lightning in the sky can be seen. The lightning will then zap both tesla rods, sending a surge of power around the city, causing the power to disable.

Step 2: Police Chopper Battle
Once the power is out, an armed police chopper with a spotlight will be sent into the map to investigate. Not knowing about the survivors, the chopper attempts to kill them. The players much now shoot down the police chopper by focusing fire at the tail rotor. Every time it is damaged, the chopper will begin to circle around the map, dropping bombs which can down a player almost instantly. Once done its bombing run, the players can now focus on shooting the tail rotor again. Once damaged a second time, the helicopter will then do another bombing run again. Once done, the chopper will then do a strafing run with two miniguns. The chopper will continue doing this until both miniguns are shot out by the player. The player can then shoot its tail rotor again until it is destroyed. The chopper will then spin out of control and crash into the doorway of the tallest building in the area, allowing access into the building.

Keep in mind when fighting the chopper that the zombies will still attack the player. It is advised to keep a crawler and keep it out of the open so the chopper doesn't kill it.

Step 3: Ending
Enter the building and ascend the staircase to the top of the building. Interact with the door at the top, revealing a helipad with a Harrier VTOL jet on it, which was placed there by the rift. Entering the Harrier will play the end cutscene, showing the four characters heading directly into the center of the rift as they are then transported to another dimension as the the words "TO BE CONTINUED..." can be seen on the screen. The match will end and the achievement will be unlocked.

Rewards
Completing the achievement will award the players 2000 XP. A green checkmark will also be present at the bottom right hand corner of the map selection screen.

Trivia

 * The achievement picture is the same as the "Time Paradox" achievement in Call of Duty: Modern Warfare Remastered.