2000 V70 SE, Denso, AW-55, 217K miles

Going to need some help diagnosing this, since there are cascading symptoms and don't quite know where to start the troubleshooting. Car ran fine on the way into work (12 mile commute one way); then about half way home the following occurred (AC on) in about this sequence:

- Alternator warning light lit dimly, then off, then blinked, then full bright
- ABS and TRACS lights on, SRS light on
- Brake failure light on
- Engine started losing power, I turned AC off
- Odometer zeroed out; the numbers turned to dashes all the way across
- Speedometer quit working
- Car struggled up final hill before home
- Pulled into driveway, engine surging a bit
- Stopped and shifted into Park gear, engine still running but at slightly higher RPM than idle speed
- Had to use shiftlock release button to return gear selector to drive
- Loud transmission clunk when shifting from Park, to Drive to Reverse, car didn't want to move when throttled and in gear
- Back into Park, another clunk, engine quit
- Won't restart, turn key and hear click, but starter won't engage
- Odometer now has number readout again, instead of dashes displayed earlier

That's a lot of symptoms to list, I know. Happened quickly with no warning signs before the drive home. By the way, head lights still illuminate brightly and central locking still works. I do feel fortunate to have made it home and not breaking down on the road.

Where to begin?