Harry Potter and the Philosopher’s Stone starts with an unusual day for Mr. Vernon Dursley from Privet Drive, who sees a lot of strange things like people in weird cloaks and a cat reading maps and signboards. Eventually, it is revealed that these people are all wizards or witches and are celebrating a great historic event – that of the vanquishing of the Dark Lord Voldemort. James and Lily Potter are killed tragically by Voldemort, but he is unable to kill their son Harry Potter.

Albus Dumbledore, the headmaster of Hogwarts, orders Hagrid to safely get Harry Potter from the wreckage of his house and then leaves him at the doorstep of the Dursleys who are Harry’s only blood relatives.

After about 10 years, on another unusual day, a lot of letters addressed to Harry are delivered by owls to Privet Drive. Uncle Vernon takes his wife Petunia, his son Dudley and his nephew Harry Potter far away hoping to prevent these letters from coming. However, Hagrid finds the place, delivers Harry’s letter despite protests from Uncle Vernon, and conveys to Harry that he is in fact, a wizard. 

The next day Hagrid and Harry travel to London to purchase his school items. They visit several places including the Gringotts bank from where Harry gets his money to buy things. Hagrid also visits a vault and collects a small package from there and claims that it’s ‘top secret’ when Harry asks him about it. Harry also gets his new wand from Ollivanders and is told by Mr. Ollivander that his wand is related to the wand of Lord Voldemort and that both their cores contain phoenix feathers from the same bird.

Harry then boards the Hogwarts Express and meets a boy named Ronald Weasley who ends up becoming his best friend. He also meets Hermione Granger, a girl who is slightly bossy in Harry’s opinion and knows a lot more about magic even before joining Hogwarts. Harry also meets another boy called Draco Malfoy whom he doesn’t like much.

In Hogwarts, Harry is sorted into the Gryffindor house along with Ron and Hermione. During their flying lessons, Draco Malfoy, who has bullied a boy named Neville before, snatches his ‘Remembrall’ and challenges Harry Potter to fly and catch it. Harry does so with great ease and Madam McGonagall is impressed with his flying abilities. Harry Potter is recruited into the Gryffindor Quidditch team and becomes the youngest Quidditch player in a century, and helps his team win the first game. 

A newspaper report about a break-in into the Gringotts bank piques his interest as he had been to Gringotts with Hagrid the same day as the break-in. It also occurs to him that Hagrid had cleared the contents of a vault, and the report mentions that nothing was stolen during the break-in. 

Eventually, Harry, Ron, and Hermione end up encountering a dangerous huge three-headed dog when they get lost in the third-floor corridor which is out of bounds for students. In another instance, they fight off a troll. The encounter with the troll cements their friendship and the three spend most of their time together after this. Hagrid tries to tame a dragon, which he received from a stranger in a pub, names it Norbert, but is unsuccessful in taming it and is forced to send it to Ron’s brother who works with Dragons in Romania. Also, Harry is gifted with an Invisibility Cloak for Christmas, by someone who claims it was Harry’s father’s and that he is merely returning it to him.

Meanwhile, they suspect their potions teacher Snape as the perpetrator of all these incidents to get to the stone. They encounter several occasions where Snape tortures and questions another teacher, Professor Quirrell. Harry, Ron, and Hermione run into a lot of significant clues to deduce that several of these events must be related and that the dog is guarding something that was in the Gringotts vault. After some research, they find out that the item in question is something called a Philosopher’s Stone, which is very valuable. It is said to transform other base metals to gold and produce the Elixir of Life which makes its drinker immortal.

Harry and Hermione, along with Neville and Malfoy are caught roaming in the castle at night and are sent for detention to the Forbidden Forest with Hagrid. There, they encounter a dead unicorn and a cloaked figure drinking its blood. Harry’s scar starts hurting as the figure approaches him, but he is saved by a centaur called Firenze. Firenze tells Harry that the cloaked figure was a spirit of Lord Voldemort. He also hints that Lord Voldemort is trying to steal the Philosopher’s Stone from Hogwarts to regain his physical form. 

Back in the castle, Harry, Ron, and Hermione realize that the stone is not safe and that they have to act. They bravely cross several magical barriers laid by the teachers of Hogwarts to prevent anyone from getting to the stone, and finally, Harry reaches the last barrier and is surprised to find Professor Quirrell there who it turns out was the culprit all along. Quirrell is unable to get the Stone because of the challenging hurdle in the form of the Mirror of Erised about which Harry had previously discussed with Professor Dumbledore. 

It is revealed that Lord Voldemort possesses Professor Quirrell and that Voldemort’s half-formed face had been strategically hidden under Quirrell’s turban in the back of his head. Finally, Harry thwarts this attempt to steal the Stone by touching Quirrell’s hand and realizing that it disintegrates on contact with Harry’s skin. Finally, the whole school is in praise of Harry and his friends’ bravery and Gryffindor gets a lot of points for this and eventually wins the House Cup.
