How to Complete Guess Who I Saw Today in Fallout New Vegas

16 August 2026 | 30

Navigating the complex narrative paths of the Mojave Wasteland often leads players to unique settlements tucked away in the mountains. One such location is Jacobstown, a peaceful haven established for mutants seeking refuge from the hostilities of the outside world. Engaging with the community here triggers the side quest titled Guess Who I Saw Today, which delves deep into a medical mystery threatening the town stability.

Initiating the Investigation in Jacobstown

To begin this quest, you must travel to the far northwestern corner of the map and enter the lodge in Jacobstown. Inside, you will encounter Doctor Henry, a former Enclave scientist who is actively trying to cure the nightkin of their schizophrenia. Speak with him thoroughly about his experimental treatments to learn that he needs more field data regarding the local wildlife mutations.

Doctor Henry will request that you investigate a nearby cavern where the nightkin usually hunt for food. Before heading out, you should speak with Lily Bowen, a friendly nightkin grandmother who can join you as a companion. Having her in your party provides significant combat support and unique dialogue options during the upcoming investigation.

Exploring the Perilous Charleston Cave

Your next objective requires navigating toward the Charleston Cave, located just a short distance north of the main lodge. The interior of this cavern is heavily populated by cloaked nightstalkers that can catch unprepared adventurers by surprise. Utilizing VATS and high-damage melee weapons or shotguns will help you clear the tunnels efficiently.

As you delve deeper into the subterranean maze, you will eventually discover the remains of a fallen nightkin hunter lying near the back of the cave system. Inspecting the corpse closely reveals a chewed stealth boy prototype that seems to be causing the aggressive behavior in the local predators. Retrieve this crucial mechanical artifact to advance your quest log parameters.

Delivering the Prototype to Doctor Henry

With the prototype safely in your active inventory, make your way back to the Jacobstown lodge to present the findings. Doctor Henry will express immense fascination with the modified technology and decide to initiate a live test immediately. He will ask Lily to wear the device to monitor its psychological effects on her unstable mind.

During this critical experiment, a nightkin leader named Marcus or Keen may intervene depending on how you negotiate with the surrounding townspeople. Keen demands the prototype to help his people maintain their stealth advantages, forcing you to make a choice. You can use high speech skills to convince him to back down peacefully or prepare for a sudden combat sequence.

Resolving the Medical Dilemma

After handling the immediate confrontation, you must talk to Doctor Henry once more to determine the final outcome of the research. You are presented with a tactical choice regarding how to conclude the experiment safely for Lily. You can choose to alter the experiment variables, finalize the cure using the data, or terminate the project entirely to protect the test subject.

Choosing to complete the research successfully rewards you with a hefty amount of experience points and shifts your reputation positively with the local faction. Furthermore, this resolution directly impacts Lily's personal quest progression and her ultimate ending slide when the main campaign concludes. Balancing the ethical implications of the science against the safety of the mutants provides a memorable conclusion to this Mojave story.