Alyssa made another set of hand- and footholds up the wall in her new location and climbed up to take another sneak peek. She knew from what she'd seen of the sphere's direction of travel just a moment ago that it would have its back to her, but she also had to hope for some luck. If its patrol took it past the end of its current corridor and into the far end of the one she had just crossed, she should have time to slip over the wall, dash across that corridor and slip round the corner into the next one. However, if it only went as far as the end of its corridor it would be turning round to retrace its steps very shortly and it would be too risky to try to get across in that time. And it would also get tricky to stay out of sight of the previous sphere while she waited for this one to return and go past. Timing could get complicated. She hovered, her eyes barely above the top of the wall, ready to duck down not only at any sign that it was about to turn round, but also as soon as it began to turn the corner if it was indeed carrying on further - it would be side-on to her at that point and she didn't know what its peripheral vision range was like.
As she waited she was able see over the walls further ahead and take note of a few more significant details. The tops of two more droids were just visible, heading towards each other and then passing by each other a couple of corridors over. It looked like they were probably both patrolling the same circular route, but in opposite directions. As far as she could tell, they were the only other droids still left for her to get past. But possibly even more important to her than that piece of information was the sight of the rear wall of the maze directly behind them and, in the centre of it, a deep alcove with a ladder at the back. That must be the exit! Just two more droids and she would be out!
The one she was currently watching slowed and began to veer to the right. It wasn't turning round; it was going round the corner. Luck was on her side. Alyssa dropped back down behind her wall. She would have to gauge its speed and give it time to get fully round the corner. As soon as she was sure enough time had past she raised her head, checked that the coast was indeed clear, and slid over the top of the wall, landing almost silently on the other side. Straight away she crossed it and nipped round the nearby corner. She already knew from her reconnaissance just a few moments previously that the passage she was now entering was clear. Whether the sphere she had just avoided or one of the two up ahead came into it at any time she had no idea, but for now she knew that neither was on the verge of entering it.
Unfortunately, what she wasn't aware of was that the sphere patrolling the passage where she had made her previous set of indentations in the wall had just reached that spot, and noticed them. The information was promptly silently relayed via a radio link to all its colleagues. Now they were on the alert for an intruder in their maze. Instantly, they all increased their speed and rose up to allow their visual sensors to see over the walls.
Alyssa ran to the end of the dividing wall between this new corridor and the next one, and stopped to listen. She could hear a faint hum. Its position meant one of the two remaining spheres was at the same end as she was, but it wasn't close enough to be directly behind this wall. It must be in the next passage across. She remembered that the entrance into it was at the opposite end. So it should be pretty safe to take a look round the end of the wall; the sphere clearly wasn't anywhere near the opening so it wouldn't be able to see her. Keeping close to the wall she stuck her head round the end and glanced down the corridor she was about to enter. Almost instantly her attention was drawn by a movement above. There, directly opposite and looking straight at her over the corridor's far wall, was a sphere - clearly the one she had heard. It was already beginning to move, quite rapidly, towards the corridor's entrance.
What could she do? She dodged back behind the wall again and began to back up but she knew it would only win her a few seconds. Where could she go? If she went too far back the way she came she'd be running right into the path of the previous sphere. And then that one too came into view, retracing its route, now also above wall height and considerably faster than before. She was trapped.
In almost no time at all she had a droid bearing down on her rapidly from each direction and from the general hum that now seemed to be all around her she guessed that others were headed her way as well. Her mind raced. Only one possibility seemed to present itself, and that a very dubious one, but she could see no alternative. Now that the droids had risen up higher into the air, there was a fair gap between them and the floor. She had no idea about the range of the electrical fields that she new these things could generate, but in the demonstration with the rodent it had not been stunned until it was almost touching the sphere that it had tried to attack. The droids would presumably drop back down to attack as soon as they were close enough to her but, if she could react quickly enough and time it just right, when they were as close as possible but just before they dropped, might she be able to slip underneath? It was a long shot. If it didn't work she wouldn't have a second chance. She just hoped the shock wouldn't be fatal.
Alyssa steeled herself and took a deep breath as the droid ahead of her approached to within a few feet of her, then she suddenly dived at the floor, rolled with the momentum and came up on to her knees, almost as one movement, then took off at a flat-out run. The sphere's response was fast. It dropped down almost instantly and she felt the tingle of ionised air as it activated its electrical field as she went into the roll. And then it was off after her. Stealth was out of the question now. She wished she could take shortcuts over the walls - the space between them and the ceiling was large enough for her to slip through, but too small for the spheres - they could only take the long way round - but she had no time to make the necessary handholds for scaling them with the team of now fast-moving droids behind her. And there was no time to stop and see where the final sphere was. All she could do was sprint as fast as she could possibly go to the exit.
It turned out that the last sphere was in the worst location possible - directly in front of the exit alcove. It was clearly guarding it. Alyssa hoped that the sight of her hurtling towards it would draw it out, but it just remained there. What could she do? She had to get past it and she had to do it quickly - she was barely keeping ahead of her pursuer. And most likely, the two would soon start working together to trap her, or to drive her into the others which were most likely following up further behind. And this one wasn't hovering as far off the floor as the other two had been - she couldn't repeat that little stunt. There was enough space between it and the alcove to physically allow her to slip round behind it but she knew there was no chance of that unless it could somehow be distracted.
I wonder, she thought.
Without pausing she dragged her tee-shirt over her head and as she came within range she threw at the droid. Her aim was good: it landed on top of the sphere, draping down its front and obscuring what she took to be its visual sensor. For a moment nothing happened but then the droid began spinning in an effort to dislodge it and in the process moved further out from the alcove. This would be her only chance. She was gasping for breath by this stage but with a supreme effort of willpower she managed to control her breathing and steady it down until it was slow, gentle, and silent. She slowed her pace just enough to quieten the pounding of her feet and the slapping of her webbed toes against the floor, and dodged past. In a second she had reached the ladder and began ascending as fast as fast as her arms and exhausted legs would allow. She knew the second droid was close behind and it came as no surprise when it followed her in and inevitably it would rise up to meet her any second. She saw that the ladder extended into a narrow shaft above the level of the test chamber's ceiling. She was fairly sure it was too narrow for the spheres to enter, if she could just reach it in time. Just a few rungs more and she would be safe. But the sphere didn't didn't rise. It just approached the ladder near ground level. That was when she suddenly realised - the ladder was metal! It didn't need to reach her, only what she was holding on to. Just in time she entered the shaft, swung her feet from the ladder and planted them firmly against the shaft's wall on one side, braced her back against the wall on the other side and let go. She shuffled herself as far from the ladder as she could, but she was still too close for comfort. She tried to ignore it and forced her trembling legs to push her upwards, at the same time burning crevices into the wall by her hands to grab onto for extra support. It was only a short distance to the top, where she could see a trap door, but it felt like a mile. Slowly and painfully she worked her way up, inch by inch, until her head made contact with the trapdoor. Gingerly she raised an arm and tried pushing. What if it was locked? She couldn't survive here much longer. Her legs would give way and she'd fall down straight into the metaphorical arms of the droids. But it wasn't. It moved quite easily. A gentle shove sent it swinging up and back, where it hit the floor of the room above with a bang. With the utmost care, terrified that with safety literally within reach she'd make a wrong move and slip, she shuffled her body up to the opening, wedged her arms over the top and tipped herself out and on to the floor, where she lay gasping, her abused muscles too weak and exhausted to move any further.