"Out in Black Mountain a child will smack your face,
I'm saying out on Black Mountain a child will smack your face,
The babies cry for liquor, and all the birds sing bass.
Well, those people in Black Mountain are mean as they can be,
And those people in Black Mountain are mean as they can be,
Now they uses gun powder just to sweeten up their tea.
I had a man in Black Mountain, the sweetest man in town,
I had a man in Black Mountain, the sweetest man in the town,
But then he met a city gal, that's when he throwed me down."
--- Black Mountain ---
Sarapin has long been the energy mining center of the Galaxy. Before his defection to the Separatists, Count Dooku stood in this very chamber and warned that the Core Worlds' over-reliance on Sarapinir energy could make it vulnerable. And when he turned traitor and lead the Separatists, he sent his lieutenant Sev'rance Tann to seize the Sarapin energy stations. Even the relatively short occupation the Separatists managed was highly valuable to the Separatist effort.
The considerable automated defense systems installed around the already incredibly dangerous planetary surface had been significantly improved since that time, in order to prevent another attack like the one Tann had carried out. Thus, in the months before the destruction of the Death Star, a new plan was created by Alliance Intelligence. Access codes and plans for the Sarapin defense grid were obtained and a small team of slicers, engineers and SpecOps officers were infiltrated onto the planet. By diverting energy from the massive output rather than attempting a large-scale attack and occupation, and using small freighters disguised and encoded as maintenance vessels, Sarapin provided an invaluable source of high energy export to the Alliance.
After the evacuation of Yavin, during the internal security review related to the loss of the Death Star, the Rebels' activities on Sarapin were discovered through the torture of several corrupt or sympathetic Imperial insiders who had provided information to Alliance intelligence.
A frantic Imperial response was mounted, largely independent of Palpatine's oversight, preoccupied as his leadership was with the pursuit of the Alliance Fleet. Fortunately for the Alliance, the Imperial effort was so hurried and rushed that they found out about it ahead of time, through the efforts of Intelligence Agent Tyric Cole. Alliance defenses could be prepared - a ground force would hold off the attacking Imperials while the last of the energy, the espionage agents, and the disguised freighters were evacuated.
However, the careless damage caused by the hurried Imperial attack threatened to create a situation that would overwhelm all efforts. It was in this area that Squad 16782 had the most significant impact, for our purposes, by shutting down the catastrophically melting down equipment and, passing through ancient tunnels built millenia earlier, escaping in the confusion.