Harry Potter and the Half-Blood Prince

The poisonings. Two attempts on Dumbledore go wrong in a row. A cursed necklace meant for him nearly kills a student, and a bottle of mead meant for him is drunk by Ron Weasley (Rupert Grint) instead. Harry Potter (Daniel Radcliffe) saves him with a bezoar. Minerva McGonagall (Maggie Smith) gets the sharpest line of the sequence, allowing that Harry's actions were heroic and then asking why they were necessary, but the film never turns the two incidents into a sustained investigation.

The memory. Harry gets it out of Horace Slughorn (Jim Broadbent) by using his mother. The doctored version has Slughorn refuse to discuss Horcruxes at all and throw the boy out. The real one has him explain what a Horcrux is and how it works, and recoil when the older Tom Riddle (Frank Dillane) asks about splitting a soul seven times, and then retreat into asking whether this is all hypothetical, all academic. Riddle gives him the reassurance he is fishing for and calls it their little secret, and Slughorn takes it. So the lie removes both things: the explanation, and the moment he accepts the academic cover. His shame belongs to both halves. He supplied dangerous knowledge, and then chose not to press the question. The film gives that second beat a few seconds, which is why it plays thin first time through.

Sectumsempra. Harry has been working out of a second-hand potions book annotated by someone who signed himself the Half-Blood Prince. One margin note reads Sectumsempra, for enemies, underlined. He does not know what it does, uses it on Draco Malfoy (Tom Felton) in a flooded bathroom, and opens him up. Severus Snape (Alan Rickman) arrives and saves the boy's life, one of the film's clearest moments of decency from a character who is given no credit for it.

The cave. This is the film at its best. Albus Dumbledore (Michael Gambon) reads the place from the traces dark magic leaves behind, opens the entrance with his own blood, and drinks a whole basin of a potion built to break whoever swallows it, making Harry keep pouring. The locket is not there. Somebody with the initials R.A.B. has taken it, and the film never says who. When the dead rise from the water and pull Harry under, Dumbledore, barely able to stand, turns the cavern into a ring of fire and clears it. What lands is not the spectacle, it is the distance. Two hours of teenagers flailing at each other, and then one old man doing something none of them will manage for years.

Dumbledore's hand. Worth being precise, because the film gives you less than it looks like. The hand is blackened from his first appearance, Harry notices, and Dumbledore turns the question aside and promises the story another time. Later he identifies the diary and the ring as destroyed Horcruxes, and says the ring was difficult to find and even more difficult to destroy. What never arrives is the curse itself: what it is doing to him, how long he has, or whether anything was done to slow it. That comes two films later, in Deathly Hallows Part 2, where Snape treats the injury and gives him a year.

The tower. Draco has repaired the Vanishing Cabinet and let the Death Eaters in. He disarms Dumbledore and then cannot finish it, and Felton gets the best minute of his career there. Snape arrives, Dumbledore says his name and the word please, and Snape kills him.

What the film lets you think. Watch it cold and Dumbledore is begging for his life and Snape was a Death Eater all along. The film encourages that hard. It is not quite true that nothing complicates it, though. Near the start of the film Snape swears an Unbreakable Vow to Narcissa Malfoy to help Draco with his task and to carry it out himself if Draco fails. The promise is planted early and paid off here, and what it actually meant is withheld for two more films. On a first viewing the betrayal reading is the one the film hands you, while the agreement that would complicate it sits in plain sight.

Nobody defends the castle. Death Eaters walk into Hogwarts, walk through it, and walk out. Bellatrix Lestrange (Helena Bonham Carter) smashes up the Great Hall and burns Hagrid's hut on the way, and nothing stops any of it, in a building full of the most capable witches and wizards in the country with Aurors posted there because everyone expects an attack. The reason is not in the film, it is in what was taken out. The book ends with a battle inside the castle, staff and students and the Order fighting room by room. It was cut, on the grounds that a full-scale fight at Hogwarts was coming in the finale and doing one here would repeat it. Dumbledore's funeral went too, on the separate grounds that it did not fit the rhythm of the film. By cutting the battle to protect the finale and the funeral for reasons of rhythm, the film loses both its climax and its closure. What remains is the shape of an invasion with the resistance removed and a vandalism scene in the gap.

McGonagall. The best brief scene in the film. She finds Harry afterwards and says: "Potter. In light of what has happened... if you should have the need to talk to someone... You should know... Professor Dumbledore... you meant a great deal to him." She never finishes the offer. She starts it, stops, and ends on what Harry meant to Dumbledore rather than what he means to her. Harry says nothing back. It also quietly settles something the series never states. Two older women look after this boy across eight films, Molly Weasley (Julie Walters) and McGonagall, and Molly is warm by nature while McGonagall is not, which is what makes her version count. She was at Privet Drive in the first film arguing that leaving him with the Dursleys was wrong because they were the worst sort of Muggles imaginable. She put him on the Quidditch team as a first year. Six films of looking out for him with affection held behind discipline. Grandmother is closer than teacher. There is a joke in the design too: McGonagall turns into a cat and is the kindest adult in the series, and Dolores Umbridge decorated her office with kitten plates and is the cruellest person in it.

The ending. The locket is a fake. Harry says he is not coming back to school, and Hermione Granger (Emma Watson) tells him he is not doing it alone, which reassembles in one scene a trio the film spent two and a half hours keeping apart.