The events following Jherek's visit and his subsequent visit to the End of Time, convinced him he was in hell and that being even more devout was his only hope of salvation. Convinced most of Inspector Springer's men, including Sergeant Sherwood, to join him in his mission. Was returned to his own time by the Time Traveller after telling Mrs Underwood he was disowning and divorcing her.
In the revised version of The Steel Tsar Underwood is Australian and the radio operator on Rowe Island. An alcoholic who periodically disappeared, he was dumped very badly beaten on the steps of the Royal Airpark Hotel. It is perhaps ironic that someone with the surname Underwood should be a womanising alcolholic. Originally was a character named Shawcross.
In The Steel Tsar his forename is not given.