Lynda Day George's character (Casey) is absent for the mission and her replacement Mimi (Barbara Anderson) tells the IMF team in the opening that Casey in Europe has created a fake background history for her role as the friend of the murdered woman which was a way to explain her pregnancy leave of absence.
27 minutes in. The sound of the elevator starting is the same as "photon torpedoes" being fired from the USS Enterprise in Star Trek TOS.
Over four years later, Barbara Anderson, Peter Graves and Robert Reed would reunite as members of the all-star cast in the TV disaster flick SST: Death Flight (1977).