1985 Chevrolet Silverado Electrical problem

My sister-in-law borrowed my truck and left the lights on until the battery died. She got a jump and everything seemed fine. Then, about 10 minutes into her trip, the engine stalled. She tried getting a jump again but this time it would not work. I towed the truck home and found that the headlights, the horn, and the clock in the dash are the only things that have power. The solenoid doesn't click, the beep when you turn the key isn't there, there is no power to the gauges or dash-lights, and the taillights don't work.

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-Aaron