Harry Potter and the Prisoner of Azkaban

When Harry's parents were killed by Voldemort, they were hiding because they expected an attack.  They made their hiding place secret by making one of their close friends, Sirius Black, their Secret Keeper.  No one can learn a secret kept by a magical Secret Keeper unless the Keeper tells them personally.  After Harry’s parents were killed, Sirius Black was cornered by the magical police in a crowded street because they believed he betrayed his friends and helped kill them.  Thirteen bystanders died before they apprehended Black.  Eleven years have passed and Black has escaped from Azkaban, the wizard prison.  While in prison, they had heard Sirius mutter in his sleep 'he's at Hogwarts'.  Because there was a risk that Black would head to Hogwarts to kill Harry, the Minister for Magic, Cornelius Fudge, has allowed the Dementors to enter Hogwarts grounds.  Dementors are hideous creatures who suck emotions from their victims, feeding on happiness and forcing bad memories to the surface. Harry is very much affected by their powers because of the pain in his distant past.

As the school year passes, Harry learns to fend off the Dementors with the Patronus Charm.  Professor Remus Lupin, the new Defense Against the Dark Arts teacher, teaches it to Harry.  Lupin turns out to be a friend of Harry's father and of Sirius Black.  Black evades all the security measures and manages to enter Hogwarts.  Hiding out at the Shrieking Shack in Hogsmeade, the village below Hogwarts castle, Black turns out to be an unexpected ally.  He and Lupin were James Potter's closest friends, along with a wizard named Peter Pettigrew.  Sirius supposedly killed Pettigrew before he was arrested.  It turns out, however, that Pettigrew had been Secret Keeper for the Potters.  He was the one who betrayed Harry's parents and it was he not Sirius who killed the thirteen people.  While Sirius was being arrested for murder, Pettigrew changed form in the confusion and has been hiding out as Scabbers, Ron's pet rat.  James and his two friends had been able to change form.  Lupin became a werewolf and the others had become Animagi to keep him company at full moon.  Sirius and Lupin try to bring Pettigrew to justice but he escapes and returns to Voldemort.  This fulfills the first part of a prophecy uttered by Professor Trelawny, the Divination teacher, earlier that year.

                    Harry Potter and the Goblet of Fire

Since Peter Pettigrew escaped at the end of the third book, Voldemort has had an ally to help him regain his powers. This year something a little different happens at Hogwarts.  Instead of the usual school Quidditch tournament, representatives from two other prestigious schools of magic arrive to participate in the Tri-Wizard Tournament. This event has not been held for a number of years due to the danger of injury and death which became quite serious because the competitors were asked to face very difficult tests of magic. At the start of the year, all the students sixteen and older are allowed to place their names in the Goblet of Fire.  One student from each school, Hogwarts, Durmstrang and Beauxbatons, would be selected to compete. At least that's what should have happened.  However for some reason, Harry's name comes out of the goblet as a fourth competitor. The tournament is bound by a magical contract and Harry has no choice but to compete.

Harry is faced with the prospect of the daunting and dangerous tasks ahead.  The first task is to retrieve a golden egg placed with dragon eggs.  Each nest is defended by a mother dragon.  While this is supposedly a secret, all the competitors are fully aware of the test before it arrives.  Harry achieves victory in the test by summoning his broomstick and flying circles around his dragon, before scooping the egg from under its nose.  In the second task the competitors must dive into the lake to rescue the person they will miss most from the merpeople who live there.  Rather than taking Ron back to the surface as soon as he could, Harry returns last because he stayed down to make sure all the hostages were rescued.  For this he is awarded bonus points.  The final test is finding the Tri-Wizard Cup which is hidden in the center of a maze full of traps and monstrous creatures. Harry and Cedric Diggory, the other competitor from Hogwarts, touch the cup at the same time and are whisked away to a cemetery.  Here Harry once again faces off with Voldemort and again defeats him and escapes.  Cedric is not so lucky though, he is murdered by Lord Voldemort.