Alex Mercer is a commanding and strategic figure prominently involved at Dulce Base and as a leader of the Paranormal Military Squad. He plays a crucial role in overseeing operations related to communication with extraterrestrial intelligence, ensuring the team's focus and operational integrity. His responsibilities include initiating broadcasts to communicate with extraterrestrial beings, decoding alien messages, and leading the team in understanding and responding to these communications. Alex Mercer is known for his intellectual curiosity and deep involvement in the philosophical and strategic aspects of interstellar communication, viewing these interactions as a form of cosmic dialogue.

At Dulce Base, Alex Mercer collaborates with team members like Jordan Hayes, exploring secured areas and engaging in high-stakes, secretive operations. He is depicted as a thoughtful mentor, particularly to Sam Rivera, emphasizing the importance of intuition and trust beyond protocol. His leadership is characterized by a blend of determination, compliance with mission protocols, and a protective approach towards his team. Alex Mercer's role extends to analyzing cosmic signals, strategizing contact efforts, and maintaining clarity in human-alien communication. His experiences during encounters with alien signals have led to profound changes, reinforcing his role as a key decision-maker and guardian in missions that transcend traditional boundaries.