Well aware that they could draw attention (only bemused looks nothing to be scared of), Walter keeps a close eye on his own body language, and restrains himself from laughing for joy - or moving so much that he falls back out of the WiFi-free zone.

"We've found one," is all he confirms - but on top of that is the bright smile now plain on his face.

Ben can also tell any difference between focusing the eye based on camera input and focusing it based on the eye's own input.