Bill is now officially a companion and given that there's a step learning curve, Bill has a lot to pick up quickly. The Doctor very much sees himself in the role of teacher and is determined to guide Bill up to a point. As we saw at the end of (Smile) the last episode, instead of returning to London, the Tardis decides that the Doctor and Bill need to travel two hundred years into the past to a Frost Fair. It seems that the Doctor's skill at negotiating with the Tardis have grown a little out of practice from spending so much time trapped on earth keeping his vow to guard whatever is in the vault.
Bill is only the second Black companion and like Martha Jones before her, she has concern about travelling backward in time as a Black women. I love that Bill points out that slavery was still legal and that there might be dangers that she has to face based specifically upon her race. Unlike the 10th Doctor, this time, the Doctor doesn't quickly blow past her concern nor does he take a great deal of time to alleviate them though.
In the preview we are treated to an elephant of all things walking on Thames. It's impressive and in fact, the entire set this week is impressive. It's not the elephant which is the concern though, it's the "lock-less monster" living below the water, consuming people at will. The first person to die is young boy with a life straight out of Oliver. The Doctor reaches for him, attempting to stop him from being dragged under, but only manages to save his sonic screwdriver. The fact that the Doctor doesn't seem emotionally affected by watching someone die really disturbs Bill, who has never seen anything like this before. Bill wants to know how many people the Doctor has seen die. When the Doctor says he doesn't know, she wants to know how many there were when he stopped counting and he doesn't have an answer for that question either. Bill begins to get angry and demands to know if the Doctor has ever killed anyone. As Whovians, we all know that at his heart, the Doctor is a pacifist; however, he most certainly has killed in the past and will kill again. The Doctor tries to put everything into context for Bill but she has no patience for any kind of equivocation or explanation. The Doctor says that he is over 2000 years old and that he has to move on when people die otherwise more people die. That's a very telling response.
Right now, the big concern should be what is going on with the creature living below the Thames. It would be nice to take the time mourn the loss of a life, especially the loss of someone so young but if they stop, the only thing that is certain is that more people will die. When you cannot do more, sometimes you just have to move on, particularly if moving on will mean saving others.
The course of their investigation leads to them a workhouse where they learn that the creature is being kept so that Lord Sutcliffe can make bricks which he burns instead of coal, thus increasing his already vast fortune. When they arrive at Sutcliffe's home, The Doctor warns Bill to let him do the talking because she gets emotional and what is needed is calm reasoning and if necessary, a bit of charm, to be able to obtain the information they need. The Doctor's calm veneer lasts a N.Y. minute because when Sutcliffe enters the room, he flies into a rage at seeing Bill seated in one of his chairs and demands she respect her betters. Sutcliffe's rant is both racist and classist and he is rewarded by having the Doctor punch him. I must admit that I didn't see that coming, particularly because punching people isn't something the Doctor normally does. Then Capaldi does what Capaldi does best - deliver an epic monologue on what makes humanity great. Unfortunately, the Doctor's speech falls on deaf ears and instead, Sutcliffe decides to escalate his plans because if the Doctor and Bill know about the monster beneath the Thames, others might as well.
The Doctor and Bill are tied up and left in a tent on the Thames, while Sutcliffe prepares to set off explosions to split up the ice and give his monster a human buffet. After a bit of struggle the Doctor and Bill manage to free themselves but have yet to decide what to do. The Doctor says that he cannot make a decision about what to do about the creature since he isn't actually human and simply serves at the pleasure of humanity. This leaves the decision squarely in Bill's hands. Will she leave the creature imprisoned rather than take the risk of it consuming humans in revenge or will she let it go free. It's a big decision. Despite the risks, Bill decides to help the Doctor release the creature.
I have to say at this point in the episode, I found myself thinking about Kill the Moon. The Doctor gave Clara the choice of blowing up the moon or to allow whatever has been growing inside of the moon to hatch. The Doctor lays this all at Clara's feet and though she ultimately decides to choose life, she's enraged with the Doctor for putting her in that position in the first damn place. Though Clara had travelled with Smith's Doctor, in my mind this episode was 12's way of testing her. Leaving the decision in Bill's hand and claiming only to be a servant of humanity was clearly the Doctor testing Bill to see if she was worthy of travelling with him. No matter what Bill decided the Doctor would always do what he wanted anyway, particularly if it meant choosing life.
Alls well that ends well. The creature is released and makes a quick exit without killing anyone. The Doctor and Bill arrange for the homeless kids who helped them to inherit Sutcliffe's estate which lifts them out of poverty for the first time. When they return to Bill's present time, she's astounded that there are no reports about a monster living under the Thames despite how many people saw it. The Doctor points out that most of the people were drunk and that they probably cracked up what they saw to that.
Nardole arrives with his promised tea and is not at all pleased that the Doctor went on a excursion. Nardole is quick to remind the Doctor of his vow but at this point the Doctor clearly feels as though he's within the letter of his vow because of his return to moments after he left. A displeased Nardole heads down to the vault and a knocking can be heard coming from the inside. You know damn well that you counted the knocks. This time there were only three knocks and we know that the Master knocks four times. Yeah, Moffatt is playing with us.