I am trying to decide whether to tow my son's.

I am trying to decide whether to tow my son's car to the shop to have it diagnosed, or to just have it towed to a scrap yard. I'm hoping you can help. While driving on the highway, the car was driving along when the rpm's rapidly increased and it felt like the car was driving itself for a few seconds before it died. And, now the engine seems to be locked and will not start. There were no loud knocking noises, and no oil underneath the car. What do you think?