Exactly right. This is, in my mind, the true Father / Son theme. It also appears in the following places: When Donovan mentions Henry for the first time after showing Indy the inscription on the rock, When Indy and Marcus arrive at Henry's ransacked house, the above mentioned scenes after the tank chase and temple collapse, and when Indy uses the grail to heal his father. This last occurance has a cool, "twist" at the end for the reveal of Elsa. Clearly, given the scenes that it appears in - this is a (if not the) Father/ Son Theme. On a similar note, if the "Grail Knight" theme is in fact the "Father Son Theme", why then does it play so prominently when Indy discovers the tomb of THE GRAIL KNIGHT under Venice, when Indy tells his Father in the castle about THE GRAIL KNIGHT, when Indy enters the sanctum of THE GRAIL KNIGHT, and after Indy and Henry witness THE GRAIL KNIGHT standing in the crumbling temple? Granted, Henry Jones is a part of some of these scenes, but it's more specific to the Grail Knight and the Grail Legend, in my opinion.