Inside Us They’re down by the river, on a mission:
the hunt for invisible enemies begins

They move along blood vessels, silent, fast, frightening. Meeting them is scary if you don't have what it takes. The Enemy-Eating Squad are trained to help – at any time of day or night – colleagues in other units of the Security Forces, who are constantly searching for hidden intruders: a very difficult operation in an overpopulated organism with a hundred billion cells. There are enemies that try to get in through the long borders and hide, but there are also billions of illegal immigrants, who are tolerated if they offer useful services to the body, like the slave bacteria of the intestine (but they require close surveillance, in any case). These agents also have to deal with rebel groups, namely the cancer cells, that every now and again attempt to set up their own state within the nation. In short, it's extremely difficult to keep order in our body and the National Defence System has to employ huge resources to make sure everything goes smoothly, and the enemies/illegal immigrants/rebels don't take control.

Neither democracy, nor dictatorship

What kind of country is our body? Not a democracy, that’s for sure, but not a dictatorship either. It's a state where the laws were decided thousands of years ago and are still valid. Everyone knows them, and everyone applies them, without thinking (even if mutinies occur from time to time, and you get these rebels – the cancer cells, to be exact -, which are often extremely dangerous. It is true too that, the military sometimes make mistakes, potentially doing even more damage). But, as a rule, every cell of the body knows exactly what it has to do and doesn’t contest the orders it gets instantly, even if some of these "instructions" may seem unfair: for example, the front-line soldiers, who fight in close combat against the most dangerous enemies, must often commit suicide once they’ve accomplished their mission (even successfully), because this is what the ancient laws established. And no one protests. Agents often have to commit suicide, even if they have worked bravely.
It's the rule

Our body is a high-tech nation, even if certain aspects sometimes seem unfathomable. Communications, for example, take place via a very sophisticated network of thin electric cables that reach into the remotest areas, or via briefcases (hormones, alarm molecules, and others) released into the (very thick) blood vessels in every region. Thanks to a system that our brain would not have the faintest idea how to design, each case has a series of codes for ‘the eyes only’ of the recipient, which recognizes and picks it up as soon as it ‘meets it’. Obviously, errors may occur, as billions of cases are circulating in the blood at every single moment of the day. But this dispatch system works very well as a rule, and makes those we are accustomed to outside pale in comparison. It is possible that some error occurs. But the system normally works very well

Here are two briefcases addressed to the Enemy-Eating Squad: more specifically, MonoCell agents on patrol. The briefcases have been released into blood by forces who are grappling with a commando of unidentified enemies in a nearby area.
The body is made up of a long series of "buildings" without windows and without house numbers, running along the blood vessels, but Enemy-Eating agents have no problem understanding where the colleagues who have asked for help are: the instructions in the briefcases contain a kind of chemical trace, which makes it easy to find the right place. The security forces have a licence to kill aggressors, or deserters, immediately, without investigations or trials (there are no Prosecutors or Courts in our body): the nation’s ancient laws allow for this, and everything must be done as quickly as possible.

Apparent chaos

The agents move quickly up to the spot the alarm signals were sent from: there’s the usual bustle of cells, agents and briefcases all around, in a flow that appears chaotic only to those who don’t know very well how our body works. To reach colleagues engaged in the fight against the enemy, the MonoCell agents use substances that literally soften the blood vessel walls. This makes it easy to open up a breach, which will then be quickly repaired by the Maintenance Service. The agents are now inside the infected site. Corridors, stairs, inner channels: it’s a labyrinth where it’s easy to hide, for illegal immigrants. But the agents swarm in, and they’re aggressive. They don't know who the enemies are exactly or what they've done that's dangerous, but that's not their business. Their mission is simple: kill on sight any individuals unable to show a passport issued by our body. The battle is about to commence: they are very close, and really scary. Entering the buildings is easy, even if there are no doors and house numbers

The agents activate the M Function (another technological marvel, designed thousands of years ago and still used today) to boost their strength: their body is transformed instantly, losing its rounded shape, and creating extensions to envelop the enemies and kill them. As in a dark fairy tale, the MonoCell cops transmute, right in front of their stunned opponents and they become BigMouth agents. They approach the enemies, quickly scan their passport codes, and decide instantly whether to kill them. But, at the same time, they throw new cases into the river to call for more backup: the Special Troops. Unlike the BigMouth, these forces can tell the enemies apart and they know them by name. Meanwhile, they launch new briefcases into the river to bring in special troops

The BigMouth agents don't waste any time, they eat, in the real sense of the word, any enemies that present an irregular passport. The mouth expands immeasurably, the victim is swallowed, then engulfed, still alive, in a special capsule inside the agent's body: this is what the law enforcement calls the "death chamber". Corrosive and digestive fluids then flood the capsule. The enemy is dissolved in a matter of seconds (without the BigMouth being damaged), and digested by the agent itself. The military almost always win. If they don’t, very serious trouble could put the body in danger.

Once they’ve eaten an enemy, the BigMouth display its passport number on their suits (along with their police codes, to avoid misunderstandings or any confusion, and so they are mistaken for the enemy). Why are they doing this? To draw the Special Troops' attention to that particular enemy and its fellow foes, and to make the defences even more efficient, for the future. Everything has been planned, as much as possible, to maintain order in the nation-body. After killing the enemy, the agents expose their passport numbers