Try

Two weeks had passed with little but coding going on. Now they where finally ready. It was time to take the system for a testride - even if the risk was still there. He tried to forget what had happened last time, but couldn't get it all the way out of his mind.

It had started off well enough - a simple testrun, using the main paths in the system and staying well away from the border setup. But then, suddenly something changed. His moves seemed sluggish, rather than lightning fast as they should be. And in the corner of his vision a faint glow appeared.

...and he said this is not the day - but it is not yet night