Marie is the chief officer of the Unknown Organization's Antimemetics Division, specializing in anomalies that actively erase human memory. She is highly dedicated to her work, taking dangerous memory-retaining drugs to perform her duties despite their severe physical toll. Her position mandates intense secrecy, forcing her to carefully compartmentalize her professional obligations from her domestic life.

Adam is a professional concert violinist who tours with the New English Symphony Orchestra. As a civilian outside the Unknown Organization, he lacks clearance to know about his wife's daily operations, but he maintains a deep affection for her and provides a grounding presence. He demonstrates a resilient, observant nature during supernatural crises.

U-3125 is an abstract, massive antimemetic threat tracked by the Unknown Organization. It functions as a hostile idea complex that actively resists being perceived, violently lashing out at anyone who successfully grasps its existence. It represents an existential danger that forces the Antimemetics Division to employ heavy insulation and censorship to prevent its spread through human consciousness.

Mahlo serves as the director of the Unknown Organization's United Kingdom and Ireland bureau. He handles high-level administrative tasks and oversees multiple specialized departments. The antimemetic nature of his facility often leaves him vulnerable to memory gaps regarding his own staff and surroundings.

Simon is an instructor and researcher at the Antimemetics Division's Wyeleigh facility. He relies heavily on his natural curiosity and strong scientific reflexes to survive encounters with memory-consuming anomalies. Despite experiencing severe memory manipulation, he effectively leverages archival research to solve immediate threats.

Andrew is the retired founder of the Antimemetics Division. Currently in his nineties, he holds crucial historical knowledge about the Organization's past operations and earlier incarnations. He previously arranged to undergo extreme, potentially lethal medical procedures to help current leadership access his fading intelligence regarding severe anomalies.

Ed Hix is a brilliant former lead researcher who designed critical containment units and protective countermeasures for the Unknown Organization. His theoretical models and physical engineering projects form the backbone of the Antimemetics Division's defensive strategies against conceptual threats.

Designated U-4987 but affectionately nicknamed "Sunshine," this invisible, symbiotic entity closely follows Marie Quinn. It feeds on trivial knowledge and stray thoughts, but Marie actively weaponizes its antimemetic capabilities to assist her in the field, making it a valuable companion.

Oli is a field researcher-in-training at the Unknown Organization. She exhibits sharp deductive reasoning and keen observation skills, showing promise as she investigates alien artifacts and attempts to decode the history of long-forgotten civilizations.

Geoff is the head of the Hazardous Response Teams for the Antimemetics Division. He coordinates rescue efforts, manages containment protocols following field incidents, and helps verify personnel identities and security clearances during internal breaches.

Jason Lo is the former Antimemetics Chief and Marie Quinn's direct predecessor. He oversees high-stakes strategic briefings regarding theoretical anomalies and makes ruthless administrative decisions to protect the Organization's long-term survival.

Adrian Gage presents himself as an executive at UO Wyeleigh, but is actually an anomalous entity designated U-7175. He generates a localized antimemetic field to trap individuals, slowly consuming their secondary languages, skills, and professional knowledge.

Levene poses as a young assistant working for Director Mahlo. He aggressively questions the legitimacy of the Antimemetics Division and attempts to frame Marie as an unauthorized threat, using Mahlo's memory gaps to his advantage.

U-2200 is a benign, ancient abstract entity that inhabits a limestone monolith. It sustains itself harmlessly by feeding on people's bike-riding skills and acts as a conversational sounding board for Marie, offering her surprisingly mundane advice during stressful periods.