Skeletal gun barrels the length of a man's body emerged from the gloom as the two robot sentry systems sniffed us over. I judged the calibre as about the same as the Hendrix's lobby defence system, and relinquished my weapons. With a vaguely insectile chittering, the automated killing units drew back and spidered up the walls to their roosting points. At the base of the two alcoves they lived in, I could make out massive iron angels with swords.