Every Infect Game Mode run is a descent through the host, one organ at a time. Each organ has its own map, local immune cells, hazards, key guardian, cancer, music and boss, and beating the boss opens a passage to the next organ. You can't go back once you leave.
The first organ and the place to learn. Soft pink tissue full of mucus, guarded by the Mast Cell. Cells here hit at two-thirds strength so new players can find their feet.
Objective: "Find and defeat the Mast Cell"
Boss: Mast Cell, "Guardian of the nasal passage"
Key guardian: Mucin Colossus, holding the Mucolytic Enzyme. One door is sealed by a mucus plug
Cancer: Nasopharyngeal Carcinoma (destroy the nodules shielding it, then the tumor). Its assassin is the Squamous Stalker
Hazards: 2–3 mucus puddles in every room, nerve endings that fire a Sneeze Reflex, cilia carpets
Local cells: Neutrophils and Monocytes. Deeper rooms add B Cells, Macrophages, Plasmablasts and Basophils
Look: a dark rose floor inside pink membrane walls lined with swaying cilia
Music: C Dorian at 100 BPM, a sawtooth pad and a soft triangle lead with a light swing
Size: 12–16 rooms
Threat: cells deal 0.67× damage, the gentlest organ
A rushing crimson vessel. The blood flow shoves you along with every heartbeat while red blood cells stream past. Ride the current to the Plasma Cell.
Objective: "Ride the current to the Plasma Cell"
Boss: Plasma Cell, "The immune system's antibody factory"
Key guardian: Fibrin Weaver, holding the Plasminogen Activator. One door is sealed by a fibrin clot
Cancer: Leukemia (cancer cells keep dividing, so find and kill the glowing stem cell). Its assassin is the Circulating Blast
Hazards: a pulsing blood flow and solid red blood cells. There are no nerve endings here because blood has no sensory endings
Local cells: Platelets in clumps, Neutrophils, Natural Killer Cells, Complement, Macrophages, Monocytes, Plasmablasts and Basophils. Deeper rooms add Dendritic Cells, antiviral capsules, vaccine vials and Memory B Cells
Look: a deep red floor with streams of red blood cells and streaks of flow, inside a vessel wall lined with flat endothelial cells and rings of smooth muscle
Music: B-flat harmonic minor at 116 BPM with a square-wave lead
Size: 17–21 rooms
Threat: enemy damage ×1.2, enemy health ×1.85, rewards ×2.2
The immune system's checkpoint: blue follicles crowded with lymphocytes and organised by helper T cells. From here on, each organ is much harder than the last.
Objective: "Break the Follicular Helper T Cell's command"
Boss: Follicular Helper T Cell, "Commander of the germinal centre"
Key guardian: Reticular Warden (Awakened), holding the Plasminogen Activator
Cancer: Lymphoma (clones hide among harmless lymphocytes, and the germinal centre is only vulnerable while it swells). Its assassin is the Owl-Eye Mimic
Hazards: reticular fibres strung across the rooms
Local cells: Free Antibodies, B Cells, Helper T Cells, Plasmablasts, NK Cells, Monocytes, Thymocytes, Lymphoid Progenitors and Basophils. Deeper rooms add Follicular Dendritic Cells, Dendritic Cells, vaccine vials and Memory B Cells
Look: a navy floor with pale follicle rings and lymphocytes drifting past, inside a fibrous capsule of collagen strands dotted with fibroblasts
Music: C-sharp Dorian at 108 BPM, swung
Size: 18–22 rooms
Threat: enemy damage ×2, enemy health ×4, rewards ×2.8
A golden intestinal lining with finger-like villi swaying along the walls. Goblet cells lob mucus here, and the Paneth Cell guards the crypts.
Objective: "Get past the Paneth Cell's defensins"
Boss: Paneth Cell, "Keeper of the intestinal crypts"
Key guardian: Cajal Pacemaker (Awakened), holding the Mucolytic Enzyme
Cancer: Colon Carcinoma (it hides in its crypts, so watch where it surfaces and dodge the polyps' pools). Its assassin is the Signet-Ring Burrower
Hazards: peristaltic waves that sweep the room
Local cells: Neutrophils, Goblet Cells, IgA Plasma Cells, Free Antibodies, Macrophages and Eosinophils. Deeper rooms add Helper T Cells, antiviral capsules and Complement
Look: a dark amber floor, swaying villi and drifting golden specks
Music: A Phrygian at 98 BPM, the darkest and most swung theme
Size: 19–23 rooms
Threat: enemy damage ×3.2, enemy health ×6.5, rewards ×3.4
The body's filter. Rust-red hexagonal lobules, each with a dark central vein, patrolled by near-invisible NKT cells and stellate cells that leave scar tissue behind.
Objective: "Survive the Kupffer Cell's filter"
Boss: Kupffer Cell, "The liver's resident filter"
Key guardian: Polyploid Hepatocyte (Awakened), holding the Fusion Peptide
Cancer: Hepatocellular Carcinoma (it regenerates from its lobes, so kill every lobe before they regrow, then strike). Its assassin is the Hepatoid Regenerator
Hazards: bile ducts that spray jets across the room
Local cells: Neutrophils, Stellate Cells, NKT Cells, Macrophages, Monocytes and Complement. Deeper rooms add IgA Plasma Cells, antiviral capsules and vaccine vials
Look: a dark rust floor tiled with hexagonal lobules and central veins, inside walls of hepatocyte plates, rows of boxy cells with round nuclei
Music: B minor at 104 BPM, a triangle pad under a sawtooth lead
Size: 20–24 rooms
Threat: enemy damage ×7.5, enemy health ×19, rewards ×4
The blood-cell factory inside the bone: pale trabecular struts and fat cells, where megakaryocytes shed platelets and myeloblasts burst into neutrophils.
Objective: "Take over the Hematopoietic Stem Cell"
Boss: Hematopoietic Stem Cell, "Mother of every blood cell"
Key guardian: Giant Osteoclast (Ancient), holding the Mucolytic Enzyme
Cancer: Multiple Myeloma (dodge its antibody spirals when they lock on, and keep off the bone lesions). Its assassin is the Lytic Stalker
Hazards: stem cell niches you can burst for health
Local cells: Myeloblasts, Megakaryocytes, Platelets, Neutrophils, Monocytes, Plasmablasts, Eosinophils and Lymphoid Progenitors. Deeper rooms add NKT Cells, Helper T Cells and vaccine vials
Look: a bone-brown floor crossed by cream bone struts and pale fat cells, inside hard, pale bone walls honeycombed with marrow pores
Music: E-flat harmonic minor at 120 BPM, the fastest theme
Size: 21–25 rooms
Threat: enemy damage ×9.5, enemy health ×28, rewards ×4.7
The last organ, behind the blood-brain barrier: a dark violet web of neurons with sparks running along it. Every cell here takes 38% less damage from you.
Objective: "Cross the barrier and defeat the Microglia"
Boss: Microglia, "The brain's last line of defence". Beating it wins the run
Key guardian: Betz Cell (Ancient), holding the Fusion Peptide
Cancer: Glioblastoma (tendrils creep toward you and the core hops between nodes, so cut the nodes down). Its assassin is the Glial Infiltrator
Hazards: synapses that arc between neuron pairs, and the blood-brain barrier, announced as you arrive
Local cells: Astrocytes, Resident Memory T Cells, NK Cells, Monocytes, Free Antibodies, Thymocytes and Memory B Cells. Deeper rooms add NKT Cells, Follicular Dendritic Cells, antiviral capsules and vaccine vials
Look: a deep indigo floor with a web of neurons and sparks running along it, inside walls of folded grey matter with glinting synapses
Music: C Lydian at 88 BPM, the slowest and brightest theme
Size: 22–26 rooms
Threat: enemy damage ×12.5, enemy health ×34, rewards ×5.5
