The protagonist who journeys to Babylon to climb the tower, dig into the vault of heaven, and eventually discovers the cylindrical shape of the world.

Hillalum's friend and fellow miner who accompanies him on the climb and shares his early experiences and anxieties.

Leads the Elamite miners, announces their arrival at Babylon, and confers with the Egyptian foreman Senmut regarding safe tunneling.

A talkative puller who explains tower life to the miners, guides them through their first days of the climb, and bids them farewell when his crew turns back.

A puller from the second crew who lives on the tower, shows the miners the unique sunset at altitude, and explains the suspended balconies.

Kudda's wife, who lives on the tower and expresses no desire to ever visit the earth below.

Leads the Egyptian stoneworkers and provides designs for sliding granite doors to protect the tunnels from potential floods.

A worker who argues that Yahweh approves of their venture and will not flood the tower.

A pragmatic miner who debates Qurdusa, arguing that Yahweh is indifferent and will not protect them from the celestial waters.

A miner who is trapped alongside Hillalum in the flooding chamber and screams in panic when the sliding door is sealed.

A miner trapped with Hillalum and Damqiya who futilely hammers at the sealed granite door and prays as the water rises.