So the Mrs went to open the car, nothing happened. Then as she keeps pressing the key fob the alarm goes off and only stops when the battery dies, it wouldn't start no matter what she does.

Now we have a totally dead battery, car that we can't start and no idea about the correct pin code.

How do we resolve this?

Car is a 2005 Blob STi widetrack with the sigma alarm and single button key.

 

You can reset the pin code, search around, I'm sure there's a thread about I've seen recently bud.