2007 Prius Is Dead

This morning, sweetie tried to start her Prius and the car was dead. I'm thinking it might be the starting battery that's dead. However, we've had a weird recent history with the car. A couple of weeks ago I was backing it out of the garage and the engine kept dying. After a bit, I got it to run, took it for a short drive, and all seemed to be well. Took the car to the local tech for a thorough exam, got a clean bill of health, and the car was fine until yesterday afternoon.

Yesterday, the car was moved from the garage for a few hours, and then, when started to put it back in the garage, the engine would run for a brief moment and then die, just as it did two weeks ago. Eventually, the car got into the garage where it sat until a short while ago. Sweetie tried to start it and the car was dead. However, the light inside the car that goes on when the doors are opened worked. After a bit, it too died ... now the car is like a corpse. No lights, can't get the engine to react to the key or start button.

The battery, BTW, is relatively new ... about two years old. I don't want to just buy a new battery as it seems that there's an underlying issue. Any thoughts on what to check, what to ask a repair shop to look for? Give me an old slant six and I'm good, but I'm out of my element with the Prius, Thanks!

Just checked and discovered that I can't open the hatch nor any of the doors other than the drivers door.