Straight up to the roof. Get some flat trunking and paint over it just to make the cable a little less visible. If you do a neat job glueing the cable to the wall you can skip the trunking and just paint over the wire.
Break out the anglegrinder and sink the conduit into the wall
That was my initial plan - but I'm pretty sure after the last time the girlfriend will remove some body parts I'm rather attached too.