5. The identity of R.A.B
The Half-Blood Prince ends in a very frustrating way as the audience are told the excruciating fact that the horcrux that Harry and Dumbledore went to retrieve from the cave was a fake. From a note hidden inside the necklace, Harry learns that the real necklace has been replaced by an unknown person known as R.A.B, and the journey to find it was ultimately a waste!
Both the characters and audience are left wondering who this person could be, but the film is swiftly concluded before we can get our answer. It is a cliffhanger that leaves us wanting, but what if we had ALREADY been told the identity of this mysterious character?
At the start of the film, Harry accompanies Dumbledore to the home of Horace Slughorn in an effort to convince the retired professor to return to Hogwarts in the new term. During this visit, Slughorn tells Harry about his favourite students - each immortalised in a small shrine in the corner of his living room. Everything is normal enough until Slughorn mentions one student in particular, a young quidditch player by the name of Regulus Black...Regulus ARCTURUS Black.
Of course, at first glance this means nothing to the viewer, but on second viewing, it becomes clear that this is the answer to the frustrating question upon which the movie finishes. This is R.A.B!
The scene then utilises the mention of Sirius's death and a gorgeous piece of flute music to guide the viewer's attention away from this fact, but when fans look back with a sharp pair of eyes, they see that this scene is an amazingly subtle piece of foreshadowing.
The truth was right beneath our noses the entire time, and returning viewers can't help but gasp when they realise.