Cassian was still reeling from his lightning trip to Kafrene, to the point that he hadn't had any energy left to regret (or feel relieved by) the circumstance that he'd been forced to skip paying a visit to Liana and Tikus despite being so close to their bar.
If he'd been a believer, he would be certain that the Force was sending him signals about Kafrene. First, one contact, Na'aru, sets a date for them to meet and he doesn't turn up (Cassian later was informed that he'd died when his ship was blown up by a squadron of TIE's; those had targeted him when he tried to sidestep a Star Destroyer which had blocked his path right after getting out from hyperspace); secondly, on his way back to his own ship, Cassian meets Liana instead, who happens to live in the area; and finally, another contact, Tivik, chooses the same place for a rendezvous.
It wasn't that Kafrene was an odd meeting point for covert operations. The incessant presence of multiple species on the streets turned it into quite a convenient meeting point, because it was much easier to go unnoticed among the crowds. But it looked like too much of a coincidence that those linked planetoids had had so much presence in Cassian's life recently, of all the inhabited worlds in the galaxy. He supposed that anyway, life was full of those types of coincidences.
But with everything that had happened in his meeting with Tivik, Kafrene had become the least of his concerns right then.
For starters, his Partisan informant had made a revelation capable of shaking the foundations of the whole galaxy. According to what he knew, the deserter pilot from the Empire had told that he'd been sent by Galen Erso, one of the most brilliant scientist in the last decades (about whom Cassian had heard vaguely a long time ago, he didn't remember where), to convey the news that the Empire had forced Erso to build a planet destroyer, and that the combustible which fed it were tons of kyber crystals which were being extracted from Jedha, among other planets with extensive reserves of that mineral. That news alone had left Cassian shaken. If that was true, many planets and billions of people were in danger of being annihilated. The rebel base on Yavin would be one of its main targets as well, when the Empire discovered its location, what was only a matter of time. The Rebellion should act swiftly, before the Empire started to put that weapon to use.
Tivik had come to the meeting with a wounded arm and was very nervous. It was his bad luck that a pair of stormtroopers appeared right during his and Cassian's rendezvous, asking for their ID's. Cassian killed them, but other troopers would come soon and see their dead comrades. Tivik had become a liability with his incapacitating injury; he would be caught with all certainty and, nervous and frightened, and fearing death (Tivik wasn't the bravest of soldiers, it was short of a miracle that Gerrera had let him belong to the Partisans) he'd be an easy prey for the Empire's interrogation methods. That was why all agents in the Rebellion carried cyanide pills, and Cassian knew that the Partisans carried them too, but he doubted that Tivik would be brave enough to commit suicide and prevent his captors from extracting any information from him.
So Cassian chose the lesser evil and killed the informant, quickly shooting him on his back, before he had time to think better about it and lost his nerve. Poor Tivik never saw it coming. That was another stone in the bottomless pit of Cassian's conscience. Another terrible deed he'd had to do for the cause. He knew that the man's body dropping, already dead before reaching the ground, would pursue him in his nightmares. Another ghost to keep him company during the long nights.
Afterwards, Cassian had scurried to his ship, because there was no time to lose. His visit to Liana would have to wait. The planet destroyer Tivik had told about didn't stop jabbing at his gut. Since when had the Empire been building it? How long until it was operational? How did it work? Cassian had never been in such a rush to go back to base and convey the news. The sooner the Rebellion began to gather intel about the weapon, the sooner they could plan a way to sabotage it.
Cassian urged Kay to make the ship fly at full speed, explaining hastily the reason for his trepidation. For once, Kay didn't complain about having been left alone and bored and kept silent for almost all the flight, only asking the pertinent questions and offering his deductions about the new weapon. In addition, he offered the information he'd gathered in his memory bank about Galen Walten Erso, a mathematician, physicist, crystallographer and expert in energy enrichment. Born on the planet Grange, married to Lyra Erso and father to a girl named Jyn. The family had lived in Coruscant for several years, under the protection of Galen's old friend Orson Krennic, but after that, their whereabouts remained unknown.
Cassian had thanked Kay for his invaluable contribution, but they'd have to wait for Intelligence to gather the necessary information on the matter, to know more about the scientist and his involvement in the design of the planet destroyer. Considering, of course, that all that tale was true and not a ruse concocted by the Empire. But a gut feeling told Cassian that the story was genuine.
Well, they'd find out soon.
Upon arriving on base, Cassian was debriefed and he revealed everything he knew. Mothma looked as shocked as Cassian himself must have looked when Tivik told him, but Draven was much more reserved and difficult to read than the Commander. That was why he'd been appointed the chief of Intelligence. He kept a cool head practically in any situation. Hard as stone and equally ruthless. It was rumored that the Empire had killed his whole family and his heart together with them. Cassian could rely.
Cassian was then told to remain alert and on call, in case he had to be summoned at any hour, and Draven dismissed him. Cassian knew that from that same instant the general would put to work the team of his best researchers and hackers to gather all the intel they could about the planet killer, assuming that the Empire had been so sloppy as to leak any intel on the weapon (what Cassian doubted, but the Empire's arrogance was its main weakness), and about Erso, in order to add the bits silenced and omitted by the official information provided on the holonet, which was the one that Kay already had in his memory bank. And, for anything that couldn't be hacked or collected remotely, Draven had his net of spies for field work, like Cassian himself.
Now, he could only wait. But this time, his ample reserves of patience were being much more tested than he remembered before.
He feared that time was much more of the essence than ever.
