The show takes another trip to the past this week, but with a personal touch. Yaz wants to know a hidden chapter in her grandmother’s life. What she finds is a tragic tale that’s also a lesson the modern world should learn.

SPOILERS BELOW

It begins with Yaz attending a birthday party for her grandmother, or nani,  Umbreen (Leena Dhingra). Yaz gets a broken watch that he is told never to repair. For some reason, she doesn’t explain why.
Yaz begs the Doctor to send her to the past to see how her grandmom lived as a young girl. Reluctantly, the Doctor uses the broken watch to trace it to a remote part of India. They meet a man called Prem (Shane Zaza), and Umbreen as a young woman (Amita Suman) with her mom. However, Yaz learns Prem, a Hindu, is about to marry Umbreen, who is Muslim. Strange her nani never mentioned that.

Then they find out exactly where they are: the day India and Pakistan are divided. That means riots, conflict, and death all because of religion. Somehow the future of Prem and Umbreen is very uncertain, especially when his younger brother, Manish (Hamza Jeetooa), is siding with the Pakistani.

However, there’s even more trouble. A spaceship filled with Vajari assassins is nearby, and the Doctor senses them through some uncomfortable static. They’re also spotted near the body of a holy man named Bakti, who was about to marry Umbreen and Prem.
Naturally, Yaz wants to stick around to make sure her grandmother’s safe, but the Doctor wars her to be careful and “tread lightly” in her own history.

For half of the episode, the Vajari are the bad guys because of their reputation. Prem even admits he’s seen them before when they were over the body of his brother when they fought in the war in Singapore. They’re also upset when the Doctor takes an important part of their hive.
However, the effects of the Partition may be the more dangerous threat. Manish claims Prem is betraying his people for marrying Umbreen but Prem wonders why all religions couldn’t live together, as they did before the British decided to split things up. He can’t believe how people have changed when their differences are suddenly more important. “I don’t know how to protect people,” he tells Graham, “when hatred’s coming from all sides.” Graham responds by saying, “All we can strive to be is good men.”

In fact, the Vajari reveal they gave up their assassin ways when their planet was destroyed, They spent a long time sorting through the remains of their people (the dust in the tube from their hive), and mourning those who died alone. They’ve been doing that ever since, including when they found Bakti. They also read the “timewinds” to prepare to mourn those who will die in the future conflicts in the Partition. One of those will be Prem. They also know how he will die, and that they can’t stop it. The Doctor also knows she can’t stop it.

Despite knowing this, the Doctor and his crew think the wedding should take place. In fact, the Doctor marries Umbreen and Prem, and she definitely has a future as a minister (unless she already is in several galaxies). The best part of her speech is about love: “Love in all its forms is the most powerful weapon in the universe.” What Prem and Umbreen are doing is their weapon against the violent effects of the Partition, but it can only work for so long. It’s still a beautiful service, which has both Hindu and Muslim traditions. That’s how he gave her his watch, and it broke when he dropped it. She calls the watch their “moment in time” when their Hindu/Muslim union defied everything.
Yaz even finds out her grandmother wanted to go to Sheffield because it sounded exotic after seeing it on a map.

However, the timewinds can’t be stopped. It’s revealed Manish killed Bakti, and is about to kill Prem with the help of some Muslim thugs. Prem tells Umbreen and her mom to head to the forest while he tries to talk some sense into his brother. In fact, Prem notices one of the thugs actually fought with him in Siam. However, that was the past.
Seeing the look on the Doctor’s face when she hears the shot that kills Prem is unforgettable.

While Yaz’s timeline was intact, she still feels sad about this part of her grandmother’s life, and why she preferred not to talk about it. However, in what seems to be a flash-forward, Yaz comments to Umbreen about what kind of a life she had, and that she wound up in Sheffield. Umbreen says she’s happy with where she wound up because Sheffield gave her roots, her husband and her family. It would be interesting if somehow, Umbreen and the Doctor reunite. That talk will be much more interesting that the day Yaz confesses to her family about who her new friend really is…and that Umbreen will the only one who isn’t surprised.

This episode was very good because it was a historic episode which involved one of the companions and her family, and also gave a lesson of how concentrating on differences can be very destructive. It’s one we need now.

Next week, the Doctor tries to rescue someone from a super-charged version of Amazon.com.