locked out of iMac/ no guest account/ keyboard not connecting

I have a problem like this. My iMac (server) is on the login screen (and there is only me and no guest facility) and the keyboard isn't being detected. I can't log in via my MacBook as it isn't seeing the server and wont connect via Go/Connetc to Server/Recent servers etc. How do I make it see the **** thing again without having to trek off and get a wired keyboard? I am assuming the bluetooth is on somehow as my mouse is connected.