Major Lewis Krantz was a Human officer of the Earthforce Marine Corps.
In 2254, Major Krantz was in charge of a basic crew and 2,000 workers to finish construction of Babylon 4. Unbeknownst to him, a Shadow team was bringing a thermonuclear device to destroy the station, and, further, John Sheridan and a team destroyed it prematurely, the blast of which only blew out the station's sensors. Krantz would wait it out, but soon, strange readings were coming from the station's fusion reactor, reducing its power levels. He ordered the output to increase, despite his first officer's warning, since he had to anticipate possible hostiles on the station. Suddenly, the station rocked as it was pulled into a spacetime anomaly, becoming as Krantz would put it "unstuck in time."
When the station returned to normal space, Krantz sent out a distress call that was eventually picked up by Babylon 5. Cmdr. Jeffrey Sinclair led a large rescue team aboard with shuttles to help evacuate the station. When he came aboard, Krantz told him what had happened and learned that it was now 2258. They began coordinating the evacuation and Krantz also led Sinclair to interrogate Zathras, who then explained he and his allies were responsible for stealing the station – dragging it through time to be used in a Great War. Despite Zathras's protest that to remove him would kill him, Major Krantz insisted on bringing him along anyway as proof of what happened. However, while heading for the final shuttle out, Zathras was trapped by falling debris. Krantz and the others were forced to leave him behind and safely made it off the station.