Fallout Show's Cold Fusion Energy Explained: What Is It?

By Pamela Gores Posted:
Fallout cold fusion, Lucy

Fallout Season 1's finale revealed why one character was after Siggi Wilzig's decapitated head, and it has to do with cold fusion energy.

The latest Amazon Prime Video game-to-TV adaption, based on the überpopular Bethesda franchise, quickly captivated audiences with its cast and faithfulness to the source material. 

Much of the season focused on Ella Purnell's Lucy's travels across the wasteland to deliver a scientist's head to a woman named Moldaver (Sarita Choudhury). Moldaver captured Lucy's dad, and Lucy was unaware of the reasoning behind it all.

[ Fallout Show: How Did Moldaver Survive? ]

Fallout TV Series: What Is Cold Fusion Energy?

Sarita Choudhury as Lee Maldover
Amazon Prime Video

In Episode 8 ("The Beginning") of Fallout Season 1, Lucy arrives at Griffith Observatory to give Moldaver Siggi Wilzig's head in exchange for her father's release. Moldaver then reveals her motives and the truth behind Lucy's lineage.

Moldaver details how Lucy's mom, once a vault dweller, escaped the vault after realizing its water was being siphoned away. She found a nearly rebuilt civilization on the surface named Shady Sands, where Moldaver resided. Long story short, Lucy's dad, Hank, did not like this and bombed Shady Sands to eliminate the competition (and, in turn, radiated Lucy's mom to the point where she became a ghoul).

Moldaver tells Lucy that Wilzig's head contains cold fusion, a limitless energy source that doesn't contain harmful radiation effects. That energy could bring Shady Sands back, but only a Vault-Tec employee can activate it. Hence, why Lucy's dad was kidnapped.

Pip-Boy technology displaying the text 'Cold Fusion Ready'
Amazon Prime Video

Hank enters the code for the cold fusion energy after realizing he has lost Lucy's trust. After a wild series of events involving Maximus' (Aaron Moten) return, Hank's escape, and Lucy leaving with The Ghoul (Walton Goggins) to track down her father (again), Moldaver returns after the battle.

While bleeding out, Moldaver activates the cold fusion energy, finally bringing her plan to fruition.

Cold fusion energy activating
Amazon Prime Video

Lights come on all over Shady Sands, igniting power throughout the nuked city.

Maximus, left behind by Lucy and The Ghoul while unconscious, watches this unfold and has one last exchange with Moldaver before the latter dies of her wounds.

Maximus overlooking Shady Sands as power is reactivated from the cold fusion energy
Amazon Prime Video

A Revived Wasteland in Fallout Season 2?

The implications of the cold fusion energy triggered in the wasteland are endless for Fallout's future.

Now greenlit for Season 2, Fallout has many loose threads to address, including Hank's escape to New Vegas, The Ghoul's search for his pre-apocalyptic family, and Lucy's eventual return to Vault 33.

As for the cold fusion energy, Shady Sands is now (supposedly) on track to be one of the wasteland's first fully functioning cities since the bombs were dropped in 2077.

Shady Sands could become a hub for Fallout moving forward, with characters returning for supplies or repose. However, the city's energy could also potentially be used otherwise.

Whether it is powering other cities or technology (in either good or bad hands), the introduction and successful activation of cold fusion energy means the so-called apocalypse could end sooner rather than later.

And, if any vials of it are still around, Vaults 31 and 33 are filled with former Vault-Tec employees who could easily activate them. 

However, the Brotherhood of Steel may also have plans for cold fusion energy, as it has a knack for tracking down and locking away technology. Moldaver's warning to Maximus before her death that all he can do is try to stop the Brotherhood may not be for naught. 

Fallout Season 1 is streaming on Amazon Prime Video.

Read more about Fallout on The Direct:

Fallout Show: Who Dropped the Bombs?

What's In Vault 31 In Fallout TV Show? Secret Experiment Revealed

Fallout: Did Maximus Hurt Dane? Answer Revealed

Matt Berry's Multiple Fallout Show Roles Revealed

- In This Article: Fallout
Release Date
April 10, 2024
Ella Purnell
Walton Goggins
- About The Author: Pamela Gores
Pamela Gores is the Managing Editor of Copy and a writer at The Direct, where she's held these roles for over three years. A diehard MCU fan since 2012's The Avengers, she harbors an extensive appreciation for all things relating to Natasha Romanoff. Pamela serves as the main point of contact for all matters relating to editing and publishing at The Direct, maintains the staff's Writing and Publishing Guide, and helps implement all the latest copy rules, whether in-house or according to AP Style.