Weird ass electrical problem

[Mufflerless J]

ok, I've had my station wagon for a couple of weeks now.. been running fine.. untill today. I drove about 30 miles with no problem, parked, and when I tried to start it again, it turned over acouple of times, then cranked slower and slower till it stoped. I thought, no big deal, dead battery. Jumped it, tried to start it and nothing. literally. Noticed that my headlights and everything else electrical didn't work. Then I got to looking. With the positive terminal unhooked, voltage across the battery was just under 12V. When I put the positive terminal back on(which threw an abnormal amount of sparks) the voltage quickly dropped down to 1 V. So I'm thinking it's a short.. But _nothing_ works.. the lights should come on with out the key in, no go. no blown fuses either. I don't figure it would be the starter, because it only gets juice when I turn the key. any clues? All help is appreciated.

[Z_Ghost]

check the + wire all the way down to the starter , might have a short in it. Does the wire get hot when you hook it up ? Might get under the car and see if the starter is getting hot (not cranking the car) , what ever is grounding that much should get hot really fast.