OK, I’m convinced after this. Donna has gone from being my least favorite co-star when she appeared in “The Runaway Bride” to my favorite companion. I guess it must be because of her growth as an individual. We get it in spades in this episode. If you’ve ever read the old Marvel comics called “What if…?” then you can understand the concept of this episode. It’s essentially a “It’s a Wonderful Life” where we see what life was like if Donna never met the Doctor. Just like in “What if…?” stories, main characters can die and it’s very, very dark. But it’s also fascinating and gives Catherine Tate some meaty material to work with, showing yet another side to Donna.

The Doctor and Donna begin the episode on the planet of Shan Shen, a bazaar. Donna is offered a free fortune reading by a pushy Fortune Teller and half-heartedly enters a small store. The teller pushes Donna to reveal her past and finds a key moment in her life. Donna was driving with her mother and wanted to take a temp job at a large store where she was working when we first saw her during “The Runaway Bride,” and where she’d met her fiancé. But her mother pushes her to stop dreaming and take a more realistic local job. A large beetle sneaks behind Donna and crawls up her back. The Teller orders Donna not to look back and to focus. The beetle latches on and the Teller convinces Donna to agree with her mother and turn right at a road intersection.

From this point on, we follow the Donna of the past as history is changed following her decision. Very soon, we catch up to the time period of “The Runaway Bride” where the alien Racnoss attacked. Donna drives past a UNIT squadron blocking the road and carrying off a body under a sheet. A hand falls and drops the sonic screwdriver. The Doctor died without Donna there to save him. It’s at this moment that Rose officially returns. She runs up and realizes she has arrived where she wanted to but was unable to save the Doctor. She speaks to Donna but won’t reveal her name.

Following that, Donna and her mother and grandfather watch the news and learn that the Royal Hope Hospital has disappeared. It is later returned and a sole survivor explains to the reporters what happened. A medical student named Oliver Morgenstern says that his fellow student Martha Jones died fighting off invaders in the hospital. The news also shows that Sarah Jane Smith and her friends were killed stopping Florence Finnegan’s plan (you’d only know this if you’ve seen the episodes, but it’s clear that BAD things are happening to London without the Doctor around to stop them).

Rose again visits Donna and tells her she needs to go on a vacation out of London. She still won’t tell her what her name is but Donna seems to think it’s good advice considering all the stuff happening to the city.

While Donna and her family unpack their bags at an inn, a massive nuclear explosion goes off in the distance, destroying London. The news reports fill us in, showing a replica of the Titanic falling from space and crashing into Parliament (as we saw almost happened in last Christmas’ Doctor Who special).

Donna and family are just one of several million displaced people in England. The government relocates them to a small flat, which they learn they must share with a few other families, including a boisterous Italian family, trying to find the good in a horrible situation. The Nobles must live in the kitchen on the floor, with just a curtain as their doorway. Grandpa Wilf tries to cheer them up saying it’s like War Time, but Donna points out they aren’t at war. Wilf nevertheless tries to keep his daughter and granddaughter in good spirits saying the U.S. has stepped up and has promised to deliver millions of dollars in foreign aid, so they won’t be so badly off for too long.

Unfortunately, we then cut to the families gathered around a tv set, learning that the U.S. has been devastated by alien Adipose being born out there, killing off millions. The U.S. is no longer able to offer aid.

Donna wanders off into the streets to get some air, despite Wilf’s warnings that it’s dangerous. Rose tells her she’s needed and stares at Donna’s back. The whole story, Donna has been feeling like something is there, but when she turns around, she’s always fine. Rose explains that The Sontarans attacked and tried to turn Earth into a breeding world but were stopped by Torchwood, who all died blowing up the Sontaran lead spaceship (and Jack, who couldn’t die, was taken prisoner back to Sontar). Rose urges Donna to come with her, even though she will die, but Donna refuses.

How can Rose transport herself into this world? It isn’t explained yet, but my guess is something bad is happening elsewhere that is causing the walls of reality to weaken. I guess we’ll find out in a week or two, one way or another. Rose WOULD know about the dangerous events though, because her parallel world that she was dropped off in was slightly ahead of Donna’s.

A few weeks later, the Italian family is ordered by the government to get in military transports, to relocate to “work camps.” Donna assumes they are being relocated but Wilf explains that it’s just like what happened in World War 2, with immigrants being the first to be persecuted. Back in the house, Donna’s mother looks miserable and Donna says she must be a big disappointment to her. Her mother actually agrees out loud. DEPRESSING!

Donna goes outside to look at the stars with Wilf only to see them blink out all across the sky. Donna realizes the world has gone to hell and goes out into the streets and sure enough, finds Rose. Donna says she’s ready.

Rose takes Donna to a UNIT base where they have the TARDIS hooked up to a bazillion cables. There’s hardly any energy left but they’ve been able to reverse engineer it just enough to fashion a time machine. Sidenote, this actually is somewhat plausible within Doctor Who continuity. The Second Doctor was reprimanded by his fellow Time Lords because they aren’t supposed to interfere with the outside universe. As punishment, they forced him to regenerate and stranded him on Earth in the 20^th Century, wiping his knowledge of how to operate the TARDIS. As the Third Doctor, he spent his time working for UNIT and trying to remember how to operate his time machine. Therefore, UNIT would have access to all of the Doctor’s research on it.

Anyway, Rose activates the system and everyone, including Donna, can finally see the massive beetle attached to her back. She of course freaks the hell out. Eventually, Rose calms her down enough to explain what’s going on. The beetle is in “temporal flux” and can’t be removed, but that means that Donna is also in a point of flux. If they can send Donna back in time, she can prevent herself from turning right and set the timeline correct. Donna agrees to do it but when she asks if she will get to live after all this, Rose remains silent.

Donna still agrees and is sent back to the day she turned, but realizes she was sent a half mile off course. With time counting down, Donna dashes for the intersection but realizes she won’t make it in time. She has a moment of clarity where she understands how important this decision will be for the world and throws herself in front of a van. This causes traffic to back up and the Donna in the car with her mother decides to turn left after all, instead of dealing with the traffic accident.

As Donna lays dying in the street, Rose comes up to her and whispers two words to pass on to the Doctor. Cut to Shan Shen. The beetle falls off of Donna’s back and the Teller is terrified at Donna’s force of will and runs away. The Doctor enters and recognizes the beetle as one of the Trickster’s brigade (The Trickster was a villain from Sarah Jane Adventures who caused people to make different decisions in the past and fed off the chaos that followed). Normally the beetle only affects the person it attaches itself to, but in Donna’s case it created a whole parallel world with its repercussions. The Doctor muses on why alternate realities seem to form around Donna (“Forest of the Dead”) and why there are so many seeming coincidences that drew the two of them together twice.

Donna insists she is nothing special, but the Doctor vehemently disagrees, saying she is brilliant. This triggers Donna’s memories of Rose from the parallel world and she describes the lady she saw. The Doctor seems to grasp that it’s Rose being described (she could never say her name, remember) and becomes worried. Donna tells him about Rose’s warning that “darkness is coming” and that Rose had whispered two words to her to pass on.

Those words? “Bad Wolf.” In an echo of the series 1 finale, the Doctor runs out of the TARDIS only to see every word transformed into Bad Wolf. This can only be a message from Rose, who once merged with the energy of the TARDIS and placed those words subconsciously throughout the universe to push the Doctor towards a pre-arranged set of events. The TARDIS’ cloister bell begins going off, as it only does when the most dangerous emergencies… emerge. Donna asks what “bad wolf” means. The Doctor answers, “the end of the universe.”

Pretty awesome cliffhanger. In a sense this was a standalone episode even though its final moments and Rose’ appearance set the stage for the coming two-part finale. I think it worked well all-around. It was a gripping, emotionally charged drama that showed us both how important the Doctor is and Donna’s inner character. She went on an Odyssey to hell and back. If I had to complain about anything, it’s that Billie Piper’s performance as Rose is…weird. It’s not great. She keeps her mouth closed and sort of mumbles her lines. Some fans have speculated she had work on her teeth. I don’t know. It’s not anything that ruins the show or distracts heavily unless you’re watching for it. Wonderfully paced and acted, this episode gets ANOTHER five out of five sonic screwdrivers!