The Typhon Expanse was a region of space with unusual temporal properties. Part of the Expanse was located in the Typhon sector. In the 24th century, the Federation facilities Deep Space 4 and Deep Space 5 were located near the Expanse.
In 2368, Helena Bourget undertook a medical mission for the Arkrand Society and did not contact any members of her family for over four months. As one of the Starfleet vessels assigned to explore the Expanse, the USS Huntly discovered her and her ship safe and sound, accompanying her to Starbase Expanse 3. (Star Trek: The Cantabrian Expeditions: "Breaking Benjamin")
By 2372, Starfleet devoted more resources to exploring and colonising the Typhon Expanse and the area surrounding it. The USS Cantabrian was one of the starships assigned to the area around the Typhon Expanse, and Starfleet took over and built several starbases in the area, including Starbase Expanse 3, Starbase Expanse 4 and Starbase Expanse 12. The Devil's Cradle was also on the edge of the Typhon Expanse. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part One", "Catalyst, Part Two", "An Innocent Time")