Robert looked down at where his son was pointing, amongst the shrubs and weeds of the public park gardens, at a brilliant blue leafed plant. Its veins seemed to pulse a dark purple. Robert was captivated, watching it move slightly out of synch with the gentle breeze carrying the stench of the nearby city. His son ran forward to get a closer look but Robert instinctively reached out a hand to stop him. As he did so he saw the shimmering leaves stop moving and then appear to give out signs of some distress. Suddenly the colour faded, the plant's death accelerated as though a stop-motion film and all that was left was grey, dried out remains. He grabbed a stick, prodded the remains briefly and then stepped towards it to pull it from the ground. This was no easy task as its roots appeared to have been strangled by the other shrubbery around it. Examining it in his hands it looked just like any other dead plant, there seemed to be nothing to hint at the peculiarities of its life, with no reason that anyone would pay it any attention.

The next day Robert drove into work with the dead plant in an old shoebox on the back seat. His wife, Rebecca, had thought him crazy for wanting to find out more about it.

"You've never been interested in plants before," she had said. Robert had kept quiet and continued to tape up the box he had transferred it to. Rebecca shrugged her shoulders in exasperation. "Well I don't want it left lying around the house."

"I'm going to put it in the garage." Robert replied. With that the subject was closed. His wife's assault had worked and he felt slightly embarrassed about his interest in the plant. Seeing it die, however, had struck a chord within him that had activated his curiosity far beyond any of his wife's taunts. Of course there was a reasonable and perfectly normal explanation and he wanted to know what it was. For the first time in months something had happened in his life that puzzled him, made him wonder, and so now he had resolved to get help.

After parking his car Robert headed straight for the lab where his friend Jim worked. He carried the box feeling uneasy about it but he knew Jim would find it interesting. He pushed his electromagnetic card against the black lock, pushed open the door as it flashed green and headed into his office building but he turned left instead of his usual right. He had known Jim for a few years and they had often gone for a drink after work although lately Robert had been busy with a new project and the long hours that come with extra responsibility. He knocked on a white door with a large glass panel and walked in. Jim was sitting at one of three desks squashed uncomfortably together. He was a tall man, his thinning hair starting to lose its dull brown colour and tired, grey eyes that fixed you with a glance. Most people found him too intimidating but Robert had hit it off with him from the start. Looking up with a smile Jim said hello. Robert smiled back and put the box down on the desk between them.

"I was hoping you could do me a favour, if you're not too busy." Robert said, proffering the loosely sealed box. "I found this yesterday and thought it looked interesting. Certainly I've never seen anything like it before. I think it's worth it."

"Well I'll take a look for you," Jim answered. "What is it?" He moved a couple of bits of paper lying on his desk to clear some space and knocked his mouse to stop the flickering screensaver that had been distracting his vision. Robert put the box down on the desk and removed the strips of tape. Jim leaned forward and opened the box. He was clearly disappointed to find a dead plant inside. "You want me just to find out what it is?"

Robert nodded, "Believe me, it's not normal. For one thing it was blue. The whole thing that is, leaves and all, not just flowers. But what really got me was the way it died. It just stopped. It went from a healthy looking, if odd, plant to that dried up bundle in less than a minute."

Jim looked sceptical, leaning backwards in his chair while reaching for to put on his glasses. "Well, I'll see what I can do. I'll call you when I get a chance, but I don't know if I'll get it done today. We're pretty backed up with samples at the moment."

Robert thanked him and walked out with a sense of excitement. He was disappointed that Jim did not seem to understand or believe that this was something strange but he knew that his investigation would show him otherwise. As he walked on to his office he realised he had not asked Jim about his family or any other of the standard aspects of life and conversation.

That morning Robert sat at his desk trying to concentrate on what he was supposed to be doing while people interrupted him with questions regarding details that he was having difficulty remembering or even caring about. He drank his coffee without tasting it, feeling less and less a part of his surroundings. When lunchtime came he went out to buy a sandwich. A growing suspicion in his mind that there was nothing extraordinary about the plant took hold and he began to feel slightly foolish.

The afternoon passed as slowly as the morning until he received an e-mail from Jim explaining that he was going out for something and would be back tomorrow to talk about the contents of the box. Robert stood up, told his colleagues he was just popping out to pick up a report and headed down to the labs hoping to catch Jim before he left.

Jim was already gone and no one there seemed to know where. "He just said there was something he had to do and he wouldn't be back today." said a young, pretty lab technician.

"Did he have a box with him?" Robert asked.

"I think so. I wasn't really paying much attention. Is it something important?"

"What? Oh, no, it's not important." Robert walked out slowly deciding to head home. He went back to his office to shut everything down and then out to his car.

He drove out through the barrier of the car park and headed left. Driving past a wasteground that had been cleared in preparation for an extension to the industrial estate where he worked he looked out to see a new thriving patch of blue. Surprised he indicated to stop and pulled over quickly. He knew they had not been there before the weekend and he climbed out of his small hatchback to get a closer look. It was clearly more examples of the plant he had found before, but each seemed to be different from the other. They shared the same strange, brilliant colour and a similar structure, but there were subtle differences in the shapes and distribution of the leaves as though each was developing their own personality, their own idea of being a plant. Grouped together Robert suddenly had an insight of them fighting to survive against the green around them. These looked a lot healthier than the one he had found the day before. A breeze blew through them, and they moved as if noticing Robert for the first time, as if whispering to themselves: There he is. With a shudder he turned around and quickly got back into his car.

Robert drove into work the next morning feeling tired and drained trying to follow the stream of traffic irregularly spurting towards the city. The subject of the plant seemed unimportant against the other worries in his life but it continued to probe its way through his mind. His previous evening had been spent unconsciously watching TV while his wife sat in sullen silence at his mood. His night had passed in a fitful sleep punctuated by little eternities of listening to the silence.

When he arrived he went straight to Jim's lab. Jim was sitting at his desk, as he had been the day before. This time he did not say hello. He looked like he had been infected by the same vague nervousness and wonder as Robert. The box Robert had brought to him was not there.

"I've got to ask you," Jim began, "where did you find it?"

"I found that one in the park. Well, Joe did. But I've seen more now. There was a patch on the ground outside here. What is it?"

Jim sighed. "The truthful answer to that is I don't know. I didn't think anything of it when you gave it to me so it was lunchtime before I started looking at it. You were right, it looks like a plant but there are some odd differences. I took it to a friend at environmental health. They know a few things about exotic plants. I'm guessing it's some expensive import whose spores have gotten out. It's probably not used to the soil or conditions here which is why it's dying." Jim looked away.

"That's not all, though," said Robert, "is it?"

"No. Look, it's very odd. When you look at it close its structure is more like a crystal than cellulose, although not like any crystal I've seen. That's what tipped me off to you being right about it being unusual. Robert, I don't know what it is but it's being looked into. Some of these tests take a while to complete, though. Did you say there was a living patch near here? Seeing a sample that's alive might help a lot."

"Sure." Robert felt a wave of relief flowing through him in a recognition that some part of him had been right to worry about this.

"These things are so complex it's hard to really know. That's why I want to see a living one, see if there was some reason for its death."

They went out and walked towards the patch Robert had seen the previous afternoon. He was not surprised to see that only a few sickly looking plants remained. They were holding on better than he had expected though. Jim began to dig one up placing it in a container he had brought with him for the job.

Behind Jim Robert saw a cat lurking. It spotted him, coolly sat down and began cleaning itself.

"I know this is going to sound crazy, but it seemed to me that the plant was killed, not that it died." Robert said.

Jim was crouched down, staring. "This isn't right." He muttered.

"What is it?" Robert moved towards him.

"This plant seemed to get stronger when I pulled it out. It pulsed. I don't know." They both looked at the remaining drying shrubs. There was a sudden howl and the cat Robert had seen leapt in front of them, clawing at the remains and tearing them up. Shocked, Jim stood up, "Jesus, I see what you mean." The cat seemed to notice them suddenly and ran off into the overgrowth of bracken and stubby trees that marked the current edge of man's trespass and building.

They looked at each other, silent. Robert spoke first, "Look, I need to get to work."

"Mmm. I should get this to my friend." Jim began walking off.

"So what do you think it is? Really?" Robert asked.

Jim did not stop walking on his way back to the company building. "I don't know." He replied, a note of resignation and irritated bewilderment in his voice.

Robert went back to work, but feeling the conversation with Jim hanging over him he did not accomplish anything. He felt that Jim was holding something back from him. He must have some idea of what it is, he thought. He knew that others in his office had noticed the way he was behaving and already passing their own petty judgements. Maybe a fight with his wife, an argument with his temperamental boss. Janise, a blonde middle-aged woman who took it on herself to care about those around her, came over when he was in the kitchen making himself yet another cup of coffee as a way of avoiding his work or his worries. He wasn't even sure what it was he was supposed to be worried about.

"Is everything all right?" she asked.

Noticing her Robert looked with an unintentionally piercing glare of anger. "Yes. Everything's fine. Joe's been a little ill in the night. I haven't been sleeping well." His expression turned to one of apology mid-way through his explanation. "He's ok, just a kid bug, you know."

Uncomfortable with any further attention he shuffled off back to his desk to resume pretending to work. He looked around at the people around him feeling very alone.

After this embarrassing encounter Robert kept his head down but he managed to be able to attack his work with renewed vigour. Being forced to face explaining what was bothering him allowed him to push it away. A little bit of normality went a long way and concentrating on words and numbers that made sense to some part of him appeared to help. His coffee cooled, undrunk, and he did not notice the afternoon pass by. Then, at ten past five, the last few people shouted goodbye, his phone rang and he looked up.

"'Bye" he shouted back while his hand reached for the telephone. He spoke his name into the receiver automatically.

"It's me" came Jim's voice, "can you meet me at the Oak?"

"Uh, sure. Give me ten minutes."

The Oak was a pub where he and Jim had gone to after work, off and on, to grumble about the company and exchange news. It was close by so Robert quickly turned off his computer and got up to leave. As he drove towards the pub he saw the where the patch he'd taken Jim to had been. It was now almost completely gone except for a few whispery traces of skeleton moving in the breeze of a grey, damp day.

Robert walked into the dark, wooden confines of the pub scanning his eyes around for Jim. He saw him sat morosely at a small round table with a nearly full pint in front of him. He waved a brief hello and headed for the near empty bar. There a couple of old regulars smoked with disdain and the young bar maid smiled to take his order.

He sat down next to Jim and took a long sip at his drink. Jim looked up at him with an odd expression in his eyes. Robert noticed the open packet of cigarettes in front of him and knew something must be wrong as Jim had given up over a year before.

"When I was at the Enviromental we had a visit." Jim began. His voice was low pitched but steady. "Some kind of government agency, said they were the police."

"You mean this is something to do with the government?"

"God, no. I don't think that at all. I don't think they have any more of a clue what it is than we have, or of how to deal with it. These things seem to be popping up all over the country and I think they're trying to find out if anyone can help them."

"So what is it?"

"Well, I'm pretty convinced it's alien, although I'm not sure I want to believe it. There's components there that aren't any kind of DNA I recognise but are clearly its equivalent. It's the oddest fucking thing I've ever seen. It also appears to be quite toxic, although not to humans. I think it's kind of like a virus, but it acts on planets."

By now Robert's mind was accelerating, accepting and adjusting what Jim was telling him into his own fears, he shifted in his seat uneasily and asked,

"So the earth is fighting it off?"

"I guess." Jim looked and sounded slightly suspicious of his own conclusions.

"So what did the police have to say?"

"Nothing of any use. They weren't exactly willing to give up information, but I don't think they really know anything. They were keen on us keeping this low key, quiet."

"That patch on the wasteground is already dead, you know? I passed it on the way here."

"Then I guess we're winning." Jim said. He balefully got a cigarette out of the packet, lit it, drained his glass and stood up. "Look, I'm going home and to be honest I'm going to try and forget all abut this. I guess I'll see you around." He walked out a Robert said goodbye leaving him alone with his drink. He looked around to see if any of the patrons had been listening but clearly they had been focusing on the TV that was now on.

By the time his car arrived at his home it was beginning to get dark. As he swung into his driveway the beams of his headlights caught two small animal shapes in the bushes forming his garden border. As they ran off he saw that they were cats, carrying some scraps of something in their jaws. Instinctively Robert knew what it was and brought his car to a faster halt than he'd been planning for screeching his tires across the concrete. He opened his door and quickly walked around the car to where the cats had started their flight. He had left the car's headlights on for illumination and the light reflected off his garage to give him a reasonable clear view of what he knew he would find.

There was a small clump of the alien plant, torn and dying, trying to hide itself amongst the poorly tended shrubbery of Robert's garden. He reached out to grab it, although he knew that he did not have to, and pull it out of the ground. A human effort to defend the planet, but Robert knew that the battle had already been won even if the humans were too late to join the field. We're too wrapped up in ourselves, Robert thought to himself, we just don't believe in anything but the importance we think we have. Yet how many similar invasions had the earth already dealt with, how many more would come and still people wouldn't even know. His wife opened the door to see what was going on her thin frame silhouetted against the electric sterile interior of their home. Robert smiled to himself.

"Just saw some cats digging around." He offered by way of explanation. He dropped the leaves in his hands to the ground knowing that he could not do any more and moved to park his car. He wife shrugged a hello and went back inside, leaving the door ajar.

He took another look around before stepping into the house. He noticed the dirt on his hands and took in the slight overgrowth of plants. One of the cats he had seen earlier had returned and was skulking in the shadows. He smiled to himself: "Earth's first line of defence." He murmured. "I guess we're in good hands."