whay would happen if i wrote to non existant eeprom location?

I threw up a quick program to storr temperature values in an arduino mega 2560 eeprom, however i forgpt that its a limited space in my rush but i remember thay now, what would happen if i attemp to write to a location past the max? Anything bad? I really dont feel like going outside and fixing it today unless i have to ofcourse,

The address "wraps around". The Mega 2560 has 4096 bytes of EEPROM with an address range of 0 (0x0000) through 4095 (0x0FFF). If you try to write to address 4096 (0x1000) the value is actually written to address 0 (0x1000 & 0x0FFF = 0x0000).

Ahh, idk what but something screwed up mu mega overnight, i had ot on a nicad bateru overnight and the battery was dead when i got to it,(old battery probably dodnt hold a charge ) but its not being recognized anymore by my computer, so i tried uploading a new program wirh arduino as isp and usbasp, and both say its not responding
And with the program i had running theres no way to know if its doing anything, and after the arduino as isp attempt i dont even get the bootloader led flash
this particular mega had been burned up previously but some parts still worked for this project, well until now : /