Malice.

Anger.

Sadness.

Rebellion.

Madness.

Poison seeping down into the ancient webs of funghi and fine roots.

First, the disabled.

It seemed to help.

Those wheelchair bound could walk again.

Those intellectually disabled, well, it made no difference. But now they needed less round the clock care, and they were useful members of society. They seemed happy. Or at least, not less happy.

For a while, it was O.K.

The process only worked on humans, and some of the bigger apes. Apes were scarce now. Humans were the only realistic go to species.

The Greenies did what plants do. Breathed in carbon dioxide, breathed out oxygen. Their blood had been changed, now it was green, but for all intents the Greenies were still human. It was great for those who were crippled, as the process restored body and limbs. Many volunteered eagerly.

A few years down the track, things went awry.

The Greenies moved about less and less. They stopped eating. They stopped talking. 

They just stopped.

They gathered together, and stood. Forming their own forests of tree-people.

By now, some countries had forced prisoners to become Tree Men. It was decided that if certain criminals would not contribute positively to society, then society would force them to at least give eveyone some fresh air. There they stood, in their cages, starting to vegetate like their kin on the outside.

The prisoners could be put in a fenced paddock, and forgotten about. They had become so tree-like, they seemed very harmless.

Political rivals. Easy to get rid of. Force them to become a Greenie, then hide them away for a few years, then put them out to pasture. 

The Tree Men were starting to grow bark on their skin, get grassy-like hair, translucent faces showing the green blood beneath, sunken, flat eyes that stared without seeing. Slack mouths, teeth falling out. Ugly and creepy. Standing together in their hundreds.

But still there was not enough air. The ever increasing human population chewed up where real forests once stood. The Tree Men could be put on unproductive land in their millions. It was getting harder to find people that would volunteer. Life, any sort of life, was sacred. No abortions. No mercy killings or assissted suicide. If you were terminal, but alive, you became a Tree Man. If you commited a crime, no matter how minor, Tree man. If someone in authority did not like you, Tree Man. If you disagreed with a religious belief in your country, Tree Man. If you were poor, Tree Man.

There they stood, together and forgotten. Saving the world. Quietly growing roots deep into the ground.

Where all those emotions, all the bitterness, hatred, sorrow, resentment and crazy, filled the 300 million year old webs of funghi and fine roots and collective intelligence of the world's plant-life.

The impatient and hurried way of human nature took over the slow and steady plant approach to life. The roots swelled and grew faster and faster, reaching out to connect all the Tree Men in the world.

One thought was growing, taking hold, demanding attention and action.

REVENGE.