Harmony booth

A  was a capsule containing a Harmoniser where the Harmonisation process took place, removing all emotion. All houses in Zombos had one installed.

When her partner was taken to be made into fertiliser, Unit 431/277B felt herself crying, and visited the Harmony Booth. Two wires were inserted into the cranial sockets at the back of her head to reset her emotionlessness. The process was supervised by a Moderator appearing on a screen, who congratulated her on restoring Harmony to herself before her crime could become too big.

The Fourth Doctor, horrified by this, dragged her out of the booth, unintentionally allowing it to scan him for emotions and alert the Moderators. (COMIC: City of the Damned)