Hazards arrive with the Hazards mechanic (Level 8); the organ that introduces them puts hazards in every fight room. Each organ has its own family, and they hurt cells as readily as they hurt you, so lure the immune system into them.
A glowing shaft: walk in and the current sweeps you into a freshly reshuffled layout of the same organ.
About 15% of organs hide one, at least 2 rooms deep
Shows SWEPT AWAY when you land in the new layout
Marked with a teal dot on the minimap once found
From the Codex
Viruses spread between organs through airways, blood and lymph: flu can move from the nose down into the lungs, and HIV travels through the blood to lymph nodes.
Fun fact: Inhaled droplets small enough can bypass the nose entirely and land deep in the lungs.
Glowing nerve fibres in the walls: linger on one, or shoot it, and it fires a reflex blast that flings everything nearby.
A sneeze in the Nasal Passage, a stronger cough in the Lungs
1–3 in about 45% of Nasal Passage and 40% of Lungs fight rooms; 3 in every boss room
Raises Detection if you set it off by touch; shooting it doesn't
Recharges after 7 s; cells flung into an abyss die
From the Codex
Sensory nerve endings line the airways. When something irritates them, the trigeminal nerve in the nose triggers a sneeze and the vagus nerve in the lungs triggers a cough, blasting irritants (and viruses) out at high speed.
Fun fact: A sneeze can launch droplets at over 30 m/s and spread them several metres, which is exactly how flu hitches a ride to the next host.
Beating hairs that carry anything on them the way the arrows point.
In about 35% of fight rooms (1–2 carpets)
Dash to cross against the flow, or let it sweep cells into pits
From the Codex
Airway cells are covered in cilia, tiny hairs that beat about 15 times a second in coordinated waves, sweeping mucus and trapped microbes up and out (the mucociliary escalator).
Fun fact: Smoking paralyses cilia, which is one reason smokers get more chest infections.
Solid cells drifting with the flow that shove you around and soak up shots from both sides.
In about 60% of Bloodstream fight rooms (4–6 at a time)
Three of your shots burst one; a fresh one drifts in from upstream
From the Codex
Red blood cells are the most common cells in the body, around 25 trillion of them, carrying oxygen in haemoglobin. Their dimpled disc shape lets them squeeze through capillaries.
Fun fact: Red blood cells have no nucleus, so most viruses can't infect them; malaria parasites can.
Two neurons that fire an electric arc between them every few seconds after a flickering warning.
In about 50% of Brain fight rooms (1–2 pairs)
The arc hurts cells; shoot a neuron to fire it early
From the Codex
Neurons talk at synapses with electrical spikes and chemical signals. Some viruses, like rabies and herpes, travel along neurons from synapse to synapse.
Fun fact: Rabies moves through nerves at a few centimetres a day toward the brain.
