"Whoa, mule! What's wrong with you?" McGregor said sternly. His mule had been more and more restless for half an hour now; probably spooked by all the dogs barking, he thought. Now a wind was blowing.
Reverend Smith was walking down the lane toward McGregor's farm, and started feeling light-headed. The air smelled funny.
McGregor, seeing how no work was going to be done this morning, unhitched the mule from the plow and started walking towards the barn.
He started feeling light-headed as he unbridled the mule, and started staggering. Everything looked funny; he rubbed his eyes and saw Smith staggering towards him. He giggled; Reverend Smith staggering?
"Are you OK, Reverend? You look a little unsteady."
Smith giggled. "You don't look so steady yourself." They both started laughing uproariously. "I don't know what's so funny," Smith said, and laughed again.
"Those cows are funny!" McGregor said. "Hey! My cattle! What's wrong with them?" The cows were all spooked, terrified.
"Oh, Lord," said the preacher. "Sinkhole! Look at that tree!"
McGregor started running to the cattle pen's gate and fell down. He got up and continued to the gate, this time at a quick stagger. Smith sat down on the ground, his head spinning.
McGregor opened the gate, but he was too late for half his cattle, who had fallen into the ever-widening hole. It was certainly a sobering experience.
"Reverend!" he cried, seeing the preacher laying prostrate on the ground. He felt like his head was clearing somewhat.
The farmers could have no idea that a supernova had obliterated the Acrux system 321 years earlier, and that the gamma rays had killed everything on the southern half of the planet, and oxidized much of its nitrogen into many different and varied oxides. Something similar (except it wasn't really) had happened more than once. An exploding star had affected Earth four hundred fifty million years earlier, causing a mass extinction called the Ordovician event, for instance.
What usually caused these mass extinctions was some angry, petulant, unsociable, mean-tempered superstar who couldn't hold his mass and finally blew up under the pressure.
Planets around "nearby" stars are greatly affected by these phenomenon. On Earth-type planets, with mostly nitrogen atmospheres, much of the nitrogen combusted, producing various nitrogen oxides, mostly what protohumans who used hydrocarbons for fuel called "smog,"
The oxide affecting McGregor's farm was what is commonly known to us as nitrous oxide.
"Laughing gas" is what it's usually known as.
This supernova was different than most supernovas. It was man-made.
"Reverend? Wake up! Are you OK? Oh, Yeshuah..."
The preacher's eyes fluttered. "What happened?" he asked.
A sinkhole in my cattle pen. Whoa... look inside that hole!"