repair – Nikon D4 possible water damage

I took my D4 out for a walk yesterday. Out of nowhere it started to rain heavily. Of course I did not have any cover or whatsoever with me. I walked about 20 minutes with it through the rain back to the car. I was not worried too much since I had used other Nikon DSLRs in heavy rain multiple times in the past and they never let me down. Back in the car I turned on the camera to check if everything is okay and the camera did turn on. I did not take a picture, I just checked the upper display. I let the camera dry over night. This morning I wanted to use the camera and she did not turn on. The upper display was indicating the battery was empty so I took out the battery to charge it. In this moment I realized, that the battery was a little bit wet. I immediately got a hairdryer to get possible moisture out of the battery compartment.

A few hours later the battery was fully charged and I placed it back in the camera but the camera wont turn on. When I put in the battery the upper display shows an empty battery symbol. I also tested a second battery which wasnt in the rain with me yesterday. When I turn on the camera the green LED on the back lights up for a second as normal and also the backlight of the buttons and display work fine but I cant use the camera.

Of course when nothing helps I will have to get the D4 to a dealer but maybe you have some suggestions for me. Please let me know.