Dahh-Ren worked for Ganymede Systems aboard Chasm Forge. His smartsuit was off network when the remaining suits received a command to deactivate their living components. He was therefore one of the four survivors present when the Fourteenth Doctor arrived aboard the station. He was the only non-human survivor aboard Chasm Forge.
He disliked being called "Darren", and accused Erin Stevenson of being racist, in response to his blue skin.
He was eventually killed in Chasm Forge's Section 12 when the smartsuits instructed his own suit to disable its organic component. (DW: Those Who Lead)