Very well: unplug the computers, unplug the external drives, stick them on a table elsewhere over the weekend.
Phone line installed, return the computers to the shelves. Discover that there no longer appears to be a socket in the back of the server suitable for connecting the external drives.
Boggle. Contemplate whether one has gone entirely and irredeemably mad, whether one's memories of plugging the drive in earlier and of unplugging it on Friday had been placed in one's memory by some trickster God. Open computer with screwdriver. Discover that the Firewire 800 sockets have sheared off the Firewire 800 card.
I think we will not buy the replacement card from StarTech.