Caldwell was an expert mining engineer on the IMC expedition to Uxarieus led by Captain Dent in 2472. He was opposed to Dent's use of murder to establish IMC's mining rights on the planet. However, he was largely prevented from rebelling against Dent by Dent's threat to make him unemployable if he stepped off the company line. Caldwell was badly in debt and was therefore conflicted by Dent's promise that the Uxariean job would make him wealthy. Ultimately, however, Caldwell broke with IMC and joined the colony under its new leader, David Winton. (TV: Colony in Space)