Rrrerrerrrerr-zggt-crrrr-crch-crch-crgh when starting.

It sounded like all the teeth on the starter burned off in about a
half-second, and now there's a relay out or something because it doesn't
even think about engaging the starter.  Any ideas -- what have I done here,
and how could this happen so suddenly?  The only other thing I could think
is that I was hearing the clutch disintegrate, and now I can't start the car
because I can't throw the clutch.  But surely I would have felt the clutch
going before now.

-Isaac in Cambridge