This article or section contains information about StarCraft: Ghost, which has been declared non-canon. Elements may be taken as 'flavor lore' however.
Haggs saw action as Captain Bock's second-in-command four years after the Brood War during an operation to retake Vespene Refinery BF 1138 from the zerg. After the uncontested landing, Haggs's suggestion to conduct reconnaissance was rejected by Bock, in favor of an immediate advance. Haggs caution was bourne out when the marines were surprised by an overwhelming zerg counter-attack.