Hiro is in the U-Stor-It, but he is in reality rather than the Metaverse; he's practicing with his swords. This is right after the incident with Raven.
Enter the helicopter. A guy jumps out, introduces himself as Major Clem, and says he's working with Juanita. Hiro's presence is required. He gets a few minutes to clean up, and they're off.
They stop at a hospital. Strapped to a bed is Da5id; they put in a pacemaker to help with the convulsions, but his heartbeat is still irregular, and his face is blank.
Apparently Juanita called the paramedics right after Da5id did Snow Crash, and they brought him to the hospital to stabilize him. Unfortunately, the surgeon on duty can't tell Hiro much more than that.
Worse, the doctor talks about Da5id's condition as though it might be permanent, and as Hiro walks out, Da5id starts to babble in nonsense syllables.
Next they fly to Da5id's house. Hiro looks for the goggles Da5id would've been wearing while in the Metaverse. They only show static, but Hiro drops them, feeling kind of paranoid—because you can't be hurt by something you see in virtual reality, right? Right?
Hiro gets a beer from Da5id's fridge and remembers all the time he'd spent there with other hackers. Back in the day, yo.