Harry’s best friend is Ron, so he must be in A6. We also know that Harry’s parents (Lily and James) are in the last column.
Ron tells us that his brothers span across his diagonal, meaning that Bill must be in F1, Charlie in E2 and Percy in D3. Percy’s clue tells us that everyone in column 4 died during the Battle of Hogwarts, and so Fred must be in C4 and George in B5, as Fred was the only Weasley brother that died during the battle.
We are told from the Weasleys several other things. Bill’s clue tells us that Greyback HAS to be either in E1 or F2, as he must be adjacent to Bill, but we don’t know which one yet. Charlie tells us that the marauders have their own diagonal, but we don’t know which one yet. Percy has already helped us find Fred. Momentarily skipping over Fred, George’s clue tells us that every row apart from row A includes a Slytherin and that row A is all Gryffindors, as well as the fact that he is the only male in his row. All of this will be important for later.
Fred’s clue is the most important right now. He tells us that Ginny is adjacent to Harry but not on the same diagonal as any of her brothers. As adjacent includes diagonals, the only place Ginny can be is B2 otherwise she is on the same diagonal as her brothers. Fred also tells us that another guy Ginny dated is above her. Ginny dated Michael Corner and Dean Thomas, but only Dean was in Gryffindor, so he must go in A2.
Ginny’s clue tells us that Hermione must be in F6, as she is the only member of the Golden Trio not accounted for and F6 is the only corner left. Dean’s clue tells us that he is NEXT TO Dumbledore, and so Dumbledore must be in A3, as next to means either side, but he cannot be in A1 as Harry is there. Dean also tells us he is adjacent to Dumbledore’s deputy (McGonagall), but as yet it is unclear if she is in B3 or B1.
Aha! Dumbledore can ‘see’ McGonagall, so she must be adjacent to him as well as Dean. The only square left that both Dumbledore and Dean are adjacent to is B3 and so she must be there. Hermione’s clue tells us that Cho must be in F2, as she has to be on F row like Hermione, and has to be in the same column as Ginny – Harry’s other girlfriend.
At this point it is also possible to put in Greyback, as he has to be adjacent to Bill and E1 is the only square left that is adjacent to him.
Now we should have put in Cho, Greyback and McGonagall. Cho’s clue tells us that Sprout, Snape and Flitwick are all in this quiz and tells us that Flitwick (her head of house as she is a Ravenclaw) is diagonally adjacent to her. As we have (hopefully already) placed Greyback in E1, the only space he can be in is E3. Greyback’s clue tells us that everyone else in his column still yet to be added is a Slytherin.
Flitwick’s clue tells us that Sirius and Hagrid are in his column, but doesn’t specify in which order. However, once we think back to Charlie’s clue, there really isn’t any choice. If Sirius is in C3, then there isn’t enough spaces left on that diagonal for the rest of the marauders, but if Sirius is in F3, then the diagonal of E4, D5 and C6 will account for the other three marauders (Peter, James and Lupin) meaning Sirius must be in F3 and Hagrid must go in C3 instead. He also tells us that there is another Ravenclaw in row F, but doesn’t say where – it could be F4 or F5.
Sirius tells us that he can ‘see’ Snivellus. Snivellus is Snape and so Snape must be adjacent to him, in either E4 or F4. But wait! We’ve just determined that the only reason Sirius is in F3 is because of the marauder diagonal and so Snape cannot be a part of the diagonal, as he isn’t a marauder. E4 is part of the diagonal, so Snape must go in F4 instead. Hagrid tells us that Neville and Luna are also in the quiz. Thinking back to Flitwick’s clue, he said that the other Ravenclaw is in row F and the only space left in this row is F5. Hagrid has told us that Luna is in the quiz, and Luna is a Ravenclaw. So Luna must go in F5.
Snape’s clue reminds us of the existence of James as well as Lupin. If we think back to Harry’s clue and Percy’s clue, the order of the marauders along the diagonal becomes clear. James must be in C6 because he has to be in the sixth column, according to Harry’s clue and he has to be along Sirius’ diagonal because of Charlie’s. Lupin is the only marauder that died in the Battle of Hogwarts so he has to be in E4 because Percy told us that everyone in the fourth column died in the battle. Peter therefore must be in D5.
Snape also tells us that Lily is adjacent to James so she must be in either B6 or D6 and that Tonks must be in the same column as Lupin, in B4 or D4 (not A4 as she isn’t a Gryffindor and George said that everyone in row A is a Gryffindor.)
Luna tells us that she can ‘see’ Sirius’ brother (Regulus) and so he must be adjacent to her. The only spaces left adjacent to her are E5 and E6 so he must be in one of these, but we don’t know which.
The marauders give us a lot of info. Remus tells us that Neville is adjacent to his worst fear, which is Snape. As we should have placed Luna in F5 by now, Neville must be in E5, as this is the only space left which is adjacent to Snape. Thinking back to Luna’s clue, Regulus must therefore be in E6, as this is the only space left which is adjacent to Luna. Peter’s clue tells us that Voldemort is in the quiz and isn’t adjacent to any Slytherins. He cannot go in the top row, as these are all Gryffindors and he cannot go in the first column, as there are several Slytherins in the column, so he would be by at least one. This also means he cannot go in the second column. He cannot be in B4, as George tells us that this is a female, meaning he also cannot be in B6. He cannot be in D6 as Regulus is in E6 and Regulus is a Slytherin. Therefore he must be in either D4 or C5. James tells us that Colin and Cedric are in the quiz, which will be important later.
Neville tells us that Sprout (his Herbology teacher) is in his column. As Sprout is a Hufflepuff, she must be in C5. This also means that Voldemort is in D4. Regulus tells us that Draco and Narcissa are in this quiz and that they are on different rows. He also tells us that he is the only Slytherin in his column, so Draco must be in the second column as Regulus is in column 6, Draco can’t be in column 4 because he didn’t die and Greyback told us that there are multiple Slytherins in the first column. We don’t know if he is in C2 or D2 yet though.
Voldemort tells us that Narcissa is in his row so she must be in either D1 or D6. This means Draco must be in C2, as he cannot be in D2 as that would mean he would be in Narcissa’s row. Sprout tells us that Cedric and Tonks (as they are the two Hufflepuffs we have heard about) are the only two in the quiz and that they are on the same diagonal as her. Cedric therefore has to go in D6, as he cannot go in B6 or B4 because he’s male and George told us everyone in row B is female. Therefore Tonks must go in B4 because this completes the diagonal and Tonks was also killed during the battle. As we have filled D6, Narcissa must go in D1.
Narcissa tells us nothing. Tonks tells us that Bellatrix is in the quiz and that she must be in either B1 or B6. But wait! Snape told us that James is adjacent to Lily (Snape’s love) and Harry told us that both of his parents are in column 6, so Lily has to go in B6, meaning Bellatrix must be in B1.
Draco tells us that aside from Narcissa and Bellatrix, he is also adjacent to Pansy. After we have put in the other two, Pansy must be in C1. This also fits with Cedric’s clue that there are three women in the first column.
Pansy tells us that Lavender is close to Ron, so she must be adjacent to him – A5! Lily tells us that every boy in Harry’s dorm is in the quiz. We have Dean, Neville, Harry and Ron but we’re missing Seamus. He didn’t die in the battle so he must go in D2, leaving only A4. Who can be in A4? Look back to James’ clue! Colin is in the quiz, but we haven’t put him in yet! He died in the battle and so he can go in A4, completing the quiz.