S4·E12 The Blitz

ER trauma surgeon Anne Lindsey responds to the call for help after an explosion devastates a subway station, but when a subsequent explosion rocks the station, Anne is trapped. MacLeod remembers WWII London where he and the woman he loved, reporter Diane Terrin, were trapped in a bombed air-raid shelter during the Blitz, running out of time and air. MacLeod is desperate to rescue Anne before he loses her like he lost Diane.