I had an older Samsung SGH-x427 which was my only device to meet water and hate it. it was such a lightweight and tiny little flip-phone that it was quite easy to forget was in your pocket--which was my problem. i left it in there and forgot about it and it went through not only a wash, but dry cycle as well--oh it was shiny and smelled nice, but all i got was a white screen with tye-dye colors (but it wasn't broke but i did think it was) but then it quit working completely. i tried charging it, after letting it dry a long time in the sun, tried using it without the battery, all without success. i later went to the Battery Headquarters in town and found an aftermarket Samsung battery that fit, and it worked again! all it did was fry the battery. unfortunately, i doubt the battery in the HTC One is removable, which means you've got a problem if the same problem has happened.
Today's Li-Ion batteries have protection measures which disable the battery after x number of charge cycles from 0%, age, and improper charging, and of course, water damage. it is likely the little 'brain' has fried and disabled the battery's connection with the phone, much like a modern vehicle will display 'Vehicle Engine Disabled--Visit Service' whenever it gets wrecked and the airbags deploy.