A Voyager science officer known for his hypochondria, chosen by Janeway for a Delta Flyer mission to help the crew's weakest performers.
William Telfer is one of three underperforming crew members whom Janeway takes on a Delta Flyer survey mission in Good Shepherd, after Seven of Nine identifies them through an efficiency review. Telfer is preoccupied with imagined illnesses and is uneasy about leaving the ship.
During the mission an invisible force strikes the Flyer. Telfer is briefly dematerialised and returns with a creature writhing beneath his skin, which Janeway forces out with a phaser. When the danger peaks, he refuses to abandon ship, and all three return to Voyager with Janeway.