MY MEGANE IS DEAD

My keycard wasn't opening the door, so I managed to get in through using the manual key, wen inside the electrics were goin a bit nuts then the needles on the dials started dancing for a few seconds, now nothing comes on at all, no electrics apart from some flashing red bulb next to the speedometer, even that looks ropey.
Now being a novice I dont really know how all the car is linked together and my electronics knowlege is that of a five year old, my first thought was that the battery had died, but i didnt think that would affect my keycard / central locking.
Was just looking for any ideas as to what it could be, was thinkin my fuses, but could anyone tell me if there is fuse in the engine fuse box that protects all the in car electrics! How do you get into the fuse box in the engine
Any info is appreciated