In the second episode of the four-part story "Time-Flight," the Doctor investigates the disappearance of a Concorde jet from Heathrow Airport. In hopes of solving the mystery, the Doctor and his companions, Tegan (Janet Fielding) and Nyssa (Sarah Sutton), board a second Concorde to reconstruct the events leading up to the disappearance -- whereupon the three time travelers end up vanishing from sight themselves! First telecast March 23, 1982, "Time-Flight, Episode 2" was written by Peter Grimwade. ~ Hal Erickson, All Movie Guide