The Brain Eaters

Glenn is Elaine's fiancé and a key amateur investigator who pushes the case forward. He follows leads to the cone, fights possessed townsfolk, and stays resolute in the face of growing danger. His determination helps connect the human toll to the parasite threat and supports the plan to stop the invasion.

Elaine is Glenn's fiancée who becomes entangled in the investigation and the wider threat. She endures peril, assists in crucial scenes, and shares a moment of relief with Glenn at the end. Her resilience highlights the human cost of the crisis.

Kettering is the committee's chief investigator and a driving force behind the scientific response. He experiments with the parasite and devises a plan to kill the invaders using electricity. He is ultimately killed by a possessed ally, underscoring the personal risk scientists face in crisis situations.

Alice serves as the mayor's secretary and becomes a conduit for the parasites after being targeted. She is taken over and helps the invaders infiltrate the town, including planting a parasite in her apartment. Her arc culminates with a fatal confrontation as she is possessed and turns against Kettering.

Senator Powers leads the federal investigation into the object's origin and the murders in Riverdale. He coordinates with local authorities, attempts to issue warnings, and seeks to mobilize a broader response to the threat.

Dan Walker is the senator's assistant who participates in the investigative effort. He helps relay information and supports the cross-location coordination essential to tracing the threat.

A dying member of the missing expedition who reappears with critical information about the parasite. He utters the clue 'Carboniferous,' hinting at the creatures' ancient, Earth-bound origin and guiding the protagonists toward the cone.

An older expedition member who reveals himself to hold a higher order after the disappearance of his colleagues. He provides a cryptic link to the parasites' deeper purpose and their insertion into Earth.

The town mayor who becomes possessed and acts violently before being killed. His transformation exemplifies how the parasite can corrupt leadership and destabilize a community.

The local sheriff who is attacked and later slain, illustrating the parasite's reach into law enforcement and the danger posed to authorities on the ground.

Wyler is Kettering's assistant who accompanies him toward the cone and assists in the mission to understand and stop the invasion.

The telegrapher who attempts to warn others but is intercepted due to possession, underscoring how communication lines are compromised by the invasion.

A minor figure among the possessed characters, contributing to the sense of a town-wide threat that reaches into everyday life.