What is going on.
This is cooperative novel in the process.
So what's going on.
Pscyho's character was indeed at the University when the attack on the University took place. But he wasn't a marine, even if he thinks he is. Rather he is a special project that has gone haywire. The ghouls had found him wandering around the wastes and had brought him to the University to be checked on and investigated.
The Slayers have been after him for awhile. This as to do with the strange beeping coming from inside Psycho's corpse's head.
The University got zapped because the spy found out the ghouls were working on a special project, a project trhat might be used against either the Others or The League - their own little weapon of mass destruction. The spy also learned about the tin can found by the ghouls, so the university became a big target.
In preparation of an attack, the League sent in a drone to do a recon, not expecting it to get shot down. Their intelligence said that the air defenses of the University were not operable. But they were wrong.
The drone went down, despite the League's reports that the defenses not operating right (fixed thanks to Jim). It was enough intel to do the zap, and a mightly important zap it was. Unlikely we will see something like that for awhile. Note that the League and Slayers have not even attempted such an attack on Grey Cliffs of such a magnitude (well at least not yet).
And the Slayers had another operation. (1) to assess damage, (2) to reclaim what technology they could on the drone that might be traced back to the League, and (3) to reclaim psycho's wayward character.
But after the attack Psycho's character followed the caravan, shaken up further for having survived the attack. He might have caught up earlier but had to dig himself out of the rubble and the damage to the suit was quite bad. The ghouls had left him behind figuring that he had been destroyed in the attack.
When the Slayers came to to the University to investigate, they found the technology was gone, that the University had been indeed hit, but the special project was still not there, and that psycho's character had left as well.
One should imagine this battle as kind of a prelude to what we can expect in Chapter 4.