[ WP ] A small group of researchers on Mars begin detecting Oxygen in the air . They trace the source to a leak . A pipe leak .

Charab clicked his mandibles in irritation, vibrating a shrill call to his survey team. A chorus of cicada-like thrills answered him as they lugged fragile meteorological equipment out of the concealed tunnel. The tunnel was a deep shaft that plunged deep into Mars' crust. Deep down to the subterranean cities where the last martians took refuge from the freezing, blasted conditions on the surface. 
 
 Charab lowered his glareblocker down over his compound eyes. The harsh unfiltered sunlight stung his dark-adjusted vision. His bulky body was swaddled in the thick layers of his environmental suit but even through this he felt the bite of the Martian chill. 
 
 He signaled to his team to deploy the equipment and to begin gathering data. 
 
 His team scurried hither and thither. Squabbling and assembling the complex array of probes and filters. Charab stared out across the carmine wasteland that was his world. He thought of oceans, of the ancient legends. 
 
 He was shaken from his thoughts by one of the junior members of his team, she chattered frantically, pointing to the sensor array's display. 
 
 Charab trudged wearily over to the array's display. 
 
 He was struck dumb with disbelief, the array was detecting oxygen in the atmosphere. 
 
 Frantically Charab made his team double check their suits. A broken seal or torn panel would spell a swift death out here on the surface. His team all confirmed that their suits were intact. 
 
 The oxygen was coming from somewhere in the wasteland. 
 
 Charab pointed to two of his senior assistants, and beckoned them to follow. He dug out a small portable atmospheric probe. They were going to find the source of the oxygen, if some hereto unknown geological process was producing the life giving gas he must find it. For the good of his race. 
 
 The trio shuffled out into the rusty wasteland following the melodious'Ping' of the portable sensor. 
 
 They did n't have to go far. After they entered a steep sided canyon the sensor went wild. Charab and his assistants scrambled through the crevasse, frantically swinging their heads left and right, desperately looking for what natural marvel was once more berating oxygen into the thin air of Mars. 
 
 What they found was a white ribbed tube. 
 
 It was half buried in the red sand, meandering through a small gap in a rocky outcrop. Precious oxygen hissed out of a small tear on its side. 
 Horrified yet intrigued, Charab followed the thick coil. 
 The pipe snaked through a narrow crevice that opened up onto a broad plateau. 
 
 Charab froze. The pipe wound across the ground for several meters and into a large white dome. Dozens of these domes studded the plateau. What looked like vehicles were parked amoung the domes. 
 
 Moving among the mysterious domes were tall, skinny figures with pale, dust-ruddied skin. They only had four limbs, two to ambulate and two seemingly to manipulate their environment. 
 
 Their heads were bulbous round carapaces with a single inscrutable reflective eye. 
 
 One of the creatures turned its cyclopean gaze on Charab and his assistants. It pointed on of its forelimbs at them and scrambled backwards hastily. 
 
 Charab let out a warbling cry of alarm. The creatures had spotted him.
