You wouldn't expect to discover a resin to unplug while you were on a return trip from the South Pole, but that's exactly what happened to Ben and Tarka: we rely on technology too much.
We seem to have passed through a weird Bermuda Triangle up here near the Pole; our satellite tracking beacon is on the blink and has turned itself off twice now, with a battery indicator that goes from full to flat in a few minutes, and our spare GPS (a little Garmin Gecko) conked out a few days ago and needed a hard reset that deleted all its waypoints. In addition, our main GPS was giving us some very wonky magnetic bearings to follow as we approached the Pole, but it seems to have sorted its act out now. It's quite alarming to realise how much faith we have in these tiny gadgets, and how utterly reliant we are on them to find our depots on the way home.