When it comes to The Doctor (the titular character of BBC’sDoctor Who) there are only a few items they ever truly need to rely on: their mind, their sonic screwdriver, and lastbut certainly not least, the TARDIS.The first two they almost always have on their person, but the TARDIS is a bit trickier. It is, for all intents and purposes, its own being, complete with its own opinions and desires.

As such, sometimes The Doctor and the TARDIS become separated. This has occurred throughout the series in a variety of different ways. While the two always inevitably find their way back to one another, The Doctor without their TARDIS is at a much greater disadvantage than usual, and it makes forsome of the best episodesofDoctor Who.Here are just a few instances when The Doctor and the TARDIS have gone their separate ways.

The TARDIS is put out of commission by an ironic collision with a spaceship named “Titanic."

8Voyage Of The Damned (Christmas Special, 2007)

In a cruel twist, The 10th Doctor and his TARDIS collide with a space cruiser named “Titanic,” modeled after the real-life Titanic. The ship has come into orbit around Earth to observe the customs of a primitive species;in this case, Christmas.The TARDIS' collision forces The Doctor to put it into self-repair mode, effectively rendering it unusable for a time.

It just so happens that, during that time, the Captain of the space-faring Titanic flies the ship into a trio of meteors, killing most of the passengers and crew. As the remaining passengers are picked off by the Titanic’s robotic staff, the ship begins to fall on a collision course with Earth. The Doctor uses the heat from the Titanic’s fall to restart the engines and avert disaster, but had the TARDIS been functional, the situation likely wouldn’t have come to that.

The TARDIS picked a very inopportune time to reappear on the opposite side of the Earth

7Cold War (Series 7, Episode 8)

Throughout Series 7, The 11th Doctor faces wonky mechanical issues with the TARDIS, and as such has been tinkering with the ship’s inner workings. It just so happens that he was working on the TARDIS' “hostile action displacement system” right before arriving on a Soviet submarine at the North Pole, which had been attacked by a reanimated Ice Warrior.

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As The Doctor convinces the sub’s Captain to bring the ship to rest on an undersea ridge to prevent it from imploding, the TARDIS recognizes this as a potential “hostile action” and dematerializes. The Doctor assures Clara that the TARDIS will reappear once the danger has subsided, but in its wonky state, the TARDIS instead reappears at the South Pole. Very inconvenient.

6The Fires Of Pompeii (Series 4, Episode 2)

The 10th Doctor and Donna Noblearrive in Pompeii the day before the eruption of Mouth Vesuvius, which led to the city’s destruction. While the trip was intended as a morbid sightseeing excursion, The Doctor and Donna are trapped when a local merchant discovers the TARDIS and sells it to sculptor Lobus Cacilius.

Before The Doctor can resolve that situation, he and Donna are swept up in the prophecy of a soothsayer who predicted the arrival of “a man in a blue box,” which would precede the coming of fire and death. Eventually, that prophecy is connected to aliens called the Pyroviles, who are using Mount Vesuvius as an energy source to power their plan of conquering Earth. In the end, it is The Doctor who causes the volcano to erupt, saving the rest of Earth by destroying the Pyroviles. It is only in fleeing the devastation that he and the TARDIS are reunited.

The TARDIS is sold to a sculptor from right under The Doctor’s nose

5Utopia (Series 3, Episode 11)

As Series 3 built towards its climactic moment, a twist reveal caught The 10th Doctor off guard and allowed the TARDIS to be stolen. It all starts when The 10th Doctor, Martha,and Captain Jack Harknessencounter a lone human named Padra at the edge of the Universe. He’s fleeing for his life from the Futurekind, a race of cannibals. Padra enlists The Doctor’s help in reaching a missile silo, where a rocket is being designed to ferry the last of humanity to “Utopia.”

There they meet Professor Yana, who begs The Doctor to help fix the rocket’s engines. However, Professor Yana is hearing things: a drumbeat that has been following him his whole life. Martha spies the Professor’s watch - the same kind that The Doctor used to disguise himself as a human - but it’s too late. Professor Yanareveals himself to be The Master,and lets the Futurekind into the missile silo before stealing the TARDIS and escaping, leaving The Doctor, Martha, and Jack stranded.

Professor Yana is not who he seems

4Time Heist (Series 8, Episode 5)

WhenThe 12th Doctor answers the TARDIS' phonewhile in Clara’s flat in London, the two suddenly appear in a maximum security bank vault along with two strangers, with no memory of how they arrived there (and with no TARDIS in sight) but bearing all the equipment necessary to rob the vault of its valuables. The likely culprit of their memory loss - a set of four memory worms - lie wriggling on a central table.

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As a solar storm threatens to wipe out the bank, The Doctor and Clara find the offices of Ms. Karabraxos, the richest being in the Universe. As she packs her valuables to flee the storm, the Doctor provides Ms. Karabraxos with the TARDIS' phone number and tells her to call him if she has any regrets. In a flashback, an elderly Ms. Karabraxos calls The Doctor in Clara’s flat and shares her regrets. The Doctor is then seen planning the very heist in which he and Clara find themselves embroiled.

3The Doctor’s Wife (Series 6, Episode 4)

The Doctor doesn’t exactlylosethe TARDISin this episode; it’s there with him the whole time. The catch is, when The 11th Doctor, Amy, and Rory follow a distress call outside the known Universe and come across a lone asteroid, that asteroid - actually a sentient being named House - removes the TARDIS matrix and transplants it into a woman named Idris. So, while the TARDIS is technically present, it is no longer the TARDIS.

It turns out, The Doctor is not the first Time Lord to reach House. House has been hunting Time Lords for centuries. However, when House learns that The Doctor is the last of his race, it removes the TARDIS' matrix and attempts to implant itself into the ship as a means of escaping back into the Universe. The Doctor and Idris build a makeshift TARDIS out of scraps littered across the asteroid. They use the ramshackle ship to chase House down, eventually defeating it, but in doing so, they restore the TARDIS' original matrix. This forces a tearful goodbye between The Doctor and his oldest companion. Even though they’ll still be together, they can no longer communicate as equals.

The Doctor and Clara forget how exactly they wound up robbing a bank

2The Big Bang (Series 5, Episode 13)

Technically, The 11th Doctor loses his TARDIS at the conclusion of the episode before “The Big Bang,” but this is the episode where he must make do without it. When the TARDIS explodes, it deletes most of the Universe. All that remains is Earth, the Moon, and something akin to the Sun (which is, in fact, the still-exploding TARDIS).

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The actual events of this episode are deeply complicated, but through a series of time-travel trickeries and the use of the all-powerful Pandorica, the Doctor manages to save Amy’s life and reunite her, Rory, and himself in the present. He then flies the Pandorica into the TARDIS explosion, creating a second Big Bang, restoring both the Universe and the TARDIS to their rightful states.

1Human Nature (Series 3, Episode 8)

Part 1 of this two-part storyline sees The 10th Doctor losing not just his TARDIS,but his memories as well. Hunted by the Family of Blood, The Doctor determines that the only way to escape is to disguise himself as a human. He hides his memories in a fob watch, which he gives to Martha for safekeeping, and the two set down in 1913 England.

However, The Doctor’s turn as schoolteacher John Smith takes hold a little too well. While he still has memories of his time as The Doctor, they only appear to him in dreams. Meanwhile, the Family of Blood traces The Doctor to 1913, forcing Martha to confront “John Smith” to try and convince him to become The Doctor once again.

Things go topsy-turvy when the TARDIS becomes a living woman

The Doctor didn’t just lose the TARDIS this time, it actually blew up

The Doctor can’t fly his TARDIS if he doesn’t even know he’s The Doctor