After a tunnel was excavated, he was working when Aitrus approached with 4 Guild Masters, emissaries of the D'ni Council. To his signal, Efanis demonstrated the usage of the Cycler. As he sat at the controls, he told the Masters to keep their masks down for safety, in case the Cycler's sheath had a hole.
That night however, when only 5 spans remained uncut, an unexpected layer of diamond shattered the drill while it was digging which flew back and pierced Efanis's chest and upper arm. Other cadets gathered around him in shock beneath the burning arc lamps, as he groaned, attempting to stop the bleeding; Ta'nerin ran for help right when Telanis came with Aitrus on his side. The Master tore his cloth and inserted it in his wound, then ordered the bystanders to carry him to Master Avonis's care.
This later killing him. A small ceremony is held for him and his body is linked to another age. His death, however, inspires The Council to continue the project and expedite it by digging straight up instead of across.