In the summer of 1991
Voldemort managed to possess Hogwarts professor Quirinus Quirrell, who was
in Albania to get firsthand experience with Dark creatures and got more than he
bargained on. Once back in England with Quirrell, Voldemort kept his strength
up by consuming unicorn blood, but he needed a more lasting solution. He
decided to steal Flamel’s Philosopher’s Stone for the elixir it
would make, but Dumbledore got to it first and hid it at Hogwarts. Voldemort
(still sharing Quirrell’s body) and Harry met again in front of the Mirror
of Erised when they both broke through the stone’s protections and battled
for possession of the stone. There, Voldemort learned of a second layer of
protection from Lily’s sacrifice: Voldemort could not touch Harry without
intense pain. Dumbledore rescued Harry in time, and Voldemort abandoned
Quirrell to die. Dumbledore and Flamel later destroyed the stone.

Voldemort had been once
again thwarted by Harry Potter.

Lord Voldemort returned
to his forest in Albania in failure. He was as weak as he had ever been and
thought it would be too much to expect another foolish wizard to happen along,
and he had given up hope that his faithful Death Eaters cared what had become
of him.

But while Voldemort
waited without hope, the diary in which he had preserved the
"memory" of his "sixteen-year-old self" had been in the
possession of Lucius Malfoy, one-time Death Eater, who took an
opportunity, in August 1992, to slip the diary into a book purchased for
young Ginny Weasley at Flourish and Blotts Bookstore. Ginny opened
her heart to the diary and through it to Tom Marvolo Riddle and he
became stronger and stronger "on a diet of her deepest fears, her darkest
secrets," and he was soon more powerful than Ginny and able to use her,
without her knowledge, to open the Chamber of Secrets, release
Slytherin's basilisk, and have her act as his agent in Hogwarts.

Through her Tom learned
of Harry Potter and his victory over Lord Voldemort, who was his "past,
present and future." When Ginny became frightened and attempted to dispose
of the diary, Tom was delighted that it was found and opened by Harry. Tom was
able draw him to the Chamber to attempt to rescue Ginny because he was, by this
time, strong enough to leave the diary and wanted to learn from Harry the
secret of his survival as an infant. Tom was amused by the similarities between
himself and Harry and acknowledged that Lily Potter's sacrifice was a powerful
counter-charm, but concluded that it was "merely lucky chance," that
Harry survived and he proceeded to match his powers against Harry.

Assisted by Fawkes,
the Sorting Hat, and the sword of Godric Gryffindor, Harry killed the
basilisk but he was wounded by a basilisk fang which splintered off in his arm
as the snake died. Tom was dismayed when Fawkes healing tears saved Harry, who
then used the broken fang to defeat him by plunging it into the diary. The
venomous fang burned a hole through the diary and the memory of Tom Marvolo
Riddle passed screaming and writhing into nothingness. Harry Potter, "a
skinny boy with no extraordinary magical talent" had again defeated Lord
Voldemort.

By 1994, Voldemort had
developed new plans to fully regenerate his body. He had also acquired two
followers: Peter Pettigrew (on the run after his Scabbers disguise
was broken) and the snake Nagini (soon to be a Horcrux). With Pettigrew’s
help he made a temporary potion with unicorn blood and Nagini’s venom to
achieve a rudimentary body (a scaly baby-like form). However, full regeneration
required a potion made from bone from his father (easy), flesh from a servant
(easy), and blood from an enemy (which would have been easy if he hadn’t decided
to get it from Harry). Though he could have used the blood of any
"foe," Voldemort wanted Harry Potter, who had stripped him of power
thirteen years before and he believed "the lingering protection his mother
once gave him would reside in my veins too."

Together, Voldemort and
Pettigrew found an informant named Bertha Jorkins, tortured her for her
knowledge, and killed her. Her murder was used for Voldemort's last Horcrux,
the snake Nagini. With the information taken from Bertha, Voldemort
rescued Barty Crouch, Jr. and hatched an elaborate plan to bypass all
of Harry’s protections and bring him to the Little Hangleton graveyard for
Voldemort's rebirthing. It worked. Harry and the "spare," Cedric
Diggory, were delivered to the graveyard, where Cedric was immediately killed.
The potion worked too. Not only did Voldemort’s potion recreate his physical
body, he could now touch Harry without excruciating pain. Voldemort called a
conference of his surviving Death Eaters and demanded their renewed
allegiance.

When Voldemort tried to
duel with Harry he got another surprise: his and Harry’s wands shared the same
core (one of Fawkes’ phoenix feathers), and neither one could overpower the
other. This created the conditions for Priori Incantatem, and Voldemort
grew more and more fearful as the shades of Voldemort’s last victims were
pulled from his wand. With help from the shades of Harry’s mother and father,
Harry was able to escape to safety with Cedric's body.