Callisto Protocol Ending & Cliffhanger [Explained]

Our Callisto Protocol Ending guide will showcase the ending, final boss fight, as well as buildup to ending!

The Callisto Protocol Ending ends on a massive cliffhanger, and players can expect a boss fight to look forward to! The game has had various ups and downs regarding its gameplay aspects and how combat and movement work, but one thing that’s for sure is that it’s got a good story to it.

Note: Major spoilers ahead! Read at your own discretion.


Callisto Ending Summary
  • The Callisto Protocol ends on a rather massive cliffhanger, opening the options for a possible DLC in the future. 
  • The best way to get the ending will be by progressing fully through the main storyline. 
  • The main benefit of getting to the end will be simply that you will be able to fight the final boss as well as finish the story (as far as it is concerned)!
  • The ending reveals a lot about the warden, Ferris, Dani, Jacob as well and Dr. Mahler and leaves a lot of questions unanswered too!

Meeting Duncan Cole 

Meeting Warden
Meeting Warden (Image Credits Exputer)

The Callisto storyline builds up to a critical moment. Jacob overhears the Warden discussing the urgency of their situation and confirms Jacob’s identity as the survivor. In a tense confrontation, Jacob demands information about The Alpha and the Antidote to save Dani.

The Warden questions Jacob’s loyalty, alleging he’s not as innocent as he seems. Amidst background chants proclaiming Jacob as the survivor, he accuses the Warden of overseeing deaths and making this mission his protocol. The Warden argues the Protocol is about life, emphasizing the necessity of obstacles on the path to success.

As the Warden approaches, Jacob defensively points his gun. The Warden points to the rooftop, stating humanity’s future lies beyond space. He announces a final contest to determine the worthiness of his version of evolution. The door opens, revealing Ferris, who initiates a boss fight.

Final Boss Fight

Final Boss
Final Boss (Image Credits Exputer)

In the boss fight, Ferris begins with four punches, dodge to avoid damage. Afterward, you can melee him. He pushes you back, then kicks you. After getting up, you can counter him with melee and a gun combo. When he taunts, seize the opportunity to strike. He signals you to approach. Ferris blocks, taunts, and kicks you down again. The punching sequence resumes but after which, he then transforms into a monstrous form.

Alpha Ferris Form 

Alpha Ferris
Alpha Ferris (Image Credits Exputer)

In the second phase of the Ferris boss fight, he emphasizes the price for everything and forms a protective cocoon around his head. Aim for his head to finish the battle quickly. Watch out for his spitting projectiles, and use ranged shots on the cocoon. Be cautious of his projectiles that can reduce your HP and hinder movement.

Ferris summons crawling and exploding enemies, so prioritize eliminating them to avoid damage. Avoid melee attacks on these enemies. Alpha Ferris charges from behind, dodge his flinging motion by sidestepping. If he gets too close, dodge his punches and counter with aimed shots at the cocoon.

Keep an eye out for loot from exploding enemies, usually containing riot gun or hand cannon ammo. This is crucial in this phase. As the fight progresses, Ferris will continue spawning enemies in a repeating cycle until the battle concludes.

Final Ending

Final Ending
Final Ending (Image Credits Exputer)

After defeating Alpha Ferris, he screams briefly and falls to the ground next to a table. Jacob approaches with a DNA extraction device, stabs Ferris, and retrieves the DNA and Warden Duncan appears, claiming the DNA is the key to a long-lost dream and demands it from Jacob.

He offers an escape pod and a return to Jacob’s old life, but Jacob refuses. Dani confronts Duncan, aiming a gun. She shoots him, revealing he’s a hologram. Jacob stabs the DNA into Dani, infuriating Duncan, who activates a self-destruct sequence and departs, threatening Jacob’s fate.

Attempt To Escape 

Attempt To Escape
Attempt To Escape (Image Credits Exputer)

Jacob activates the sequence, points Dani to nearby escape pods, and urges her to go. They run through hallways with Jacob encouraging her to hurry. In a different room, Jacob spots the escape pods, but there’s only one. He forces Dani into it in a desperate moment.

Dani questions Jacob’s actions, and he apologizes for causing her harm, expressing a need to face the consequences. He activates the pod as Dani pleads with him not to. As the escape pods launch amid smoke, a voice notes the data transfer. Dani realizes Jacob gave her evidence.

In Black Iron, Jacob fights off mutations, and a hologram appears, hinting at a way out. Ferris reappears, and the scene ends, leaving a cliffhanger for the Callisto Protocol Ending.

Possible DLC 

Callisto ends on a cliffhanger due to unanswered questions about Jacob’s escape, Duncan’s fate, and Ferris reappearing. It suggests an ongoing story and a DLC is likely to provide deeper insights into Black Iron’s story and the collaboration between Dr. Mahler, Jacob, and Ferris. Jacob’s responsibility for Dani’s sister’s death and the fate of numerous people on Europa could be explored in the DLC, shedding light on Jacob’s survival.

Buildup To Ending 

Buildup To Ending
Buildup To Ending (Image Credits Exputer)

In Chapter 8, Jacob delves into Dani’s memories, discovering the hidden truth about Europa. Max intervenes, directing Jacob’s attention to Dani battling an infected creature. A woman lies lifeless on the ground as Max confesses their culpability. In a moment of sorrow, Dani clings to Lili’s lifeless body, apologizing for her failed protection.

This stark realization dawns on Jacob: Europa was not a terrorist act but a cover-up for something hidden within Black Iron. Jacob unwittingly played a role in transporting critical cargo tied to the plan. He’s confronted with the gravity of his error and faces a choice on how to make amends. The memories conclude, and Dani’s infection worsens. Jacob promises to return with a cure.

And there we have it! The entire boss fight, as well as the ending that is provided to players! And with that, we will wrap up our Callisto Protocol Ending guide! If you’re still progressing then read our Trapped Worker guide. Otherwise, if you just got the game then our Walkthrough and tips and tricks guide will get you started with useful content.    

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Mina is a Senior Guides Writer and a fanatic who’s obsessed with playing games and writing about them. She’s invested more than 2,500 hours in games like Genshin Impact and Honkai Star Rail. With a Bachelor’s Degree in Journalism, she loves to write detailed guides for beginners and pros in the Gacha Games world. You can follow Mina's gaming activity on her Steam and PSN Profiles.

Experience: 3+ Years

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