Occasionally, Toph would venture into the lower cells. She would stand, silently feeling the firebender as she sat in her cell and the cold slowly seeping into the pores of both women.
Toph never allowed Azula the knowledge that she was being watched; that her actions were being scrutinised.
These visits grew in frequency until Toph would barely go a day without casting her sight on the firebender. They would have continued, had she not accidentally made her presence known by use of a stray pebble.
Azula's confused cries, her questioning of ghosts, put an end to the metalbenders' excursions.