Doctor Who: Pandora's League, Explained
The Pandora Alliance are the secret villains of Doctor Who season 5, but their motivations and even existence were a mystery until the very last moment.

Doctor Who's "Pandora Unlocks" introduces one of the most dangerous and intimidating villains in the entire show: the Alliance of Pandora. Consisting of the Doctor's greatest enemies and the universe's most powerful warrior race, the Alliance is the universe's final push to bring down the Doctor for good. Doctor Who often sees the Doctor and his fellows travel through time and space in order to protect the universe, and while he has encountered many threatening aliens in his lifetime, it is not often that these monsters take advantage of their shared hatred of the Time Lords to abduct Together.
The League of Pandora includes some of the scariest aliens and strongest fighters in Doctor Who, the first real threat to the Doctor in a long time. "Pandora Begins" marks the end of the show's fifth season, bringing together all the loose plot threads that showrunner Steven Moffat scattered throughout each episode. It helps unravel the mystery of the time rifts - a series of deadly rifts in the universe that suck life into it and wipe it from existence. While it will take another two seasons to fully unravel the mystery," Pandorica Opens" gave us our first look at this long-running subplot.
Why Was The Alliance Formed?

As Doctor Who season 5 progressed, time rifts became increasingly dangerous, and the episode "In Cold Blood" even saw the rift kill Rory Williams and erased him from existence. Their effects were felt throughout the universe, and many species soon discovered that they were caused by the explosion of the future Doctor's TARDIS. These enemies mistakenly believed that the Doctor was the only one who could Those who piloted the TARDIS, thus banded together to trap their common opponents in an impenetrable prison and prevent the explosion from happening.
Did The Alliance Succeed?

The Alliance did manage to trap the Doctor in Pandora, but he, with Rory's help, made a Escaped soon after the bootstrap paradox. Since the TARDIS had exploded, wherever he was trapped, the Doctor piloted Pandorica into the explosion and spread its regeneration light throughout the universe, saving the day. Although the Alliance was close to almost Sheng's roster of villains, but their plans ultimately weren't enough to stop the disaster they've been operating in. It just goes to show how unknowable Rift is, which allows them to keep They've been a mystery throughout Matt Smith's tenure as the Eleventh Doctor.
Who Was Behind The Explosion Of The TARDIS?

The Alliance mistakenly believed that imprisoning the Doctor would prevent any disaster that would cause the TARDIS to explode, but it never occurred to them that it might not have been an accident at all. It was later revealed that the masterminds behind the temporary destruction of the machine were the Silencers, members of an interstellar sect dedicated to destroying the Doctor and preventing him from reaching the planet Trenzalore - where he is said to eventually die . Their intent to hunt down the Doctor wasn't made clear until season 7's "Time of the Doctor," when it was revealed that once in Trenzalore, the Doctor was faced with an impossible choice.
Silence makes the TARDIS explode to ensure he never gets the chance to make the choices he encountered in Trenzalore. There, the Doctor made contact with the Lost Time Lord, who asked him to reveal his real name to confirm that this universe was safe to enter. The Silent Ones believe the return of the Time Lord will have deadly consequences across the galaxy, and exploding the TARDIS is just one of them Several times they tried to prevent the doctor from making that choice. They came very close to beating him many times, but the Doctor was always one step ahead.