When Monk and company locate Henry for the first time, they find him manipulating a jet-fighter with his mind. The plane that he taxis around the air field before launching it is a slightly different model then the one that is shown in flight. The ground model has a permanently open cockpit and yellow markings, but the one in the air has a sealed cockpit and no markings at all.
Davis (after watching Holiday burn a hole in a fence): Ah, does it ever occur to you guys just to climb the fence?
Jeff Gulka, who plays TKO Henry here, is more well known for his multiple appearances on "The X-Files" as the character of Gibson Praise. Even though he never speaks in this episode of "Secret Agent Man", Henry is very similar to Gibson, as both are boys with powerful mental abilities fought over by powerful goverments. Though instead of being able to read minds, here he has telekinesis.
This episode differs from the rest of the series in other a few ways as well. Monk's escape (attempted) from an Agency Retrieval Team is edited together with opening credits, the only time this is ever done. As well, all the action sequences, and some of the normal ones, are freeze-framed repeatedly, which only happens once more in the entire run.
This is obviously the opening episode to the series for many reasons. While Monk and Holiday already know each other, the two meet Agent Davis for the first time here, when he is assigned as their handler. As well, he provides them with a new team perk in the Suborbital, the spy jet that they will use for the rest of the series.