Written by show-runner Steven Moffat, the Series 7, Part 2 opener finds the Doctor and his TARDIS holed up in a monastery in Cumbria, circa 1207. Mad to solve the mystery of Clara Oswin Oswald, the Doctor has, at another's suggestion (see "The Bells of Saint John: A Prequel"), "withdrawn to this place of peace of solitude that he might divine her meaning." Whether because of the friendly suggestion or desiny, a "quiet room," as it turns out, is the perfect place for impossible things to happen.

The "Bells of St. John" is, of course, a reference to the public telephone inside the Doctor's TARDIS, which, camouflaged as a police public call box, bears the emblem of the St. John Ambulance Service.

It's Clara who's calling—out of the blue—and it isn't long before she and the Doctor are reunited and back to fighting the Great Intelligence—though neither they nor we (until the end) know it. All they know is that there's "something in the Wi-Fi," "something living in the Wi-Fi—harvesting human minds"—that wants Clara's and, if it can't have it, will go to great lengths to kill her and anyone protecting her.

As in "The Snowmen," the Great Intelligence is a Bit Impotent and needs help carrying out its nefarious purposes. So, it's hacked together a cadre of Smith-like agents. After their first attempt to harvest Clara's mind is thwarted by the Doctor, she applies her insane hacking skills—and some rather ingenious social engineering—to discovering their location: Floor 65 of The Shard. But it's too late: they've found her too, and, this time, their attempt to harvest her mind succeeds. Returning from a coffee run while Clara was "setting up stuff," the Doctor discovers her seemingly lifeless body and wastes no time going into battle—not in his TARDIS, but on his gravity-defying motorcycle.

Yes; he can really do that.

In a smashing about-face, the Doctor surprises AIC Kizlet—revealing that he's not, in fact, the Doctor, but one of her spoonheads—sorry: servers—sent by the Doctor to motivate her into downloading Clara from the Great Intelligence's data cloud. Suddenly finding herself fully integrated into that cloud, Miss Kizlet panics, ordering Agents Mahler and Alexi to "Put me back…! Download me at once!" The only way that they can do that is by downloading the entire cloud and everyone trapped there.

Day saved.

Though there are casualties.

We learn that Miss Kizlet and Mahler and Alexi—all of them are also victims, controlled by the Great Intelligence, whose power has only grown as it has feasted on so many minds. As UNIT arrives at The Shard, Miss Kizlet performs a restore-to-factory-settings—returning everyone to who and what they were before.

Whether they remember or not.

Safe at home, Clara spies the Doctor's snoggbox—sorry: TARDIS—outside her window.

"So he comes back."

She teases him.

"Come back tomorrow."

Doctor: "Hello?"

Clara: "Ah! Hello! I can't find the Internet."

Doctor: "The Internet!?"

Clara: "It's gone—the Internet. I can't find it anywhere. Where is it?"

Doctor: "…Listen: where did you get this number?"

Doctor:  "Imagine that. Human souls trapped like flies in the World Wide Web. Stuck forever. Crying out for help.

Clara: "Isn't that basically Twitter?"

Doctor: "It's a time machine. You never have to wait for breakfast."

Doctor: "I can't tell the future. I just work there."

Doctor: "It's a time machine. Any time is a good time.

The last time that the Doctor answered the Bells of St. John was in the "The Empty Child," also written by Moffat. The telephone's cord was much shorter then.

As in the episodes "Asylum of the Daleks" and "The Snowmen," Clara wears red for most of "The Bells of Saint John," and, fittingly, her contemporary dress seems to borrow design elements from past and future. The necklace that she wears prominently throughout the episode (and, apparently, in the next) also seems befitting a Junior Entertainment Director aboard a starship—though, in a few close-ups, it's wings do look a bit like those of an angel.

The episode marks our third introduction to Clara "Oswin" Oswald—or "Just Clara Oswald. What was that middle one?" as she greets the Doctor. Later in the episode, she'll co-opt "Oswin"—"Clara Oswald for the win! Oswin!"—turning the middle one into a pseudonym. Of note, the etymology of Oswin is "God's friend." The meaning of Oswald is "God's power." And Clara is derived from the Latin clarus, which can be translated "bright" ("clever?") or "renowned." Also of note, the Doctor is sometimes called a god—so Oswin might also be translated "companion."

Summer Falls, the book that Artie, one of Clara's charges, is reading, is authored by Amelia Williams (i.e. Amy Pond). When Clara asks Artie "What chapter are you on?," he replies, "Ten." "Eleven is the best," Clara informs him: "You'll cry your eyes out." Could this be an allusion to something that happens to the Eleventh Doctor? Perhaps, the Fall of the Eleventh? This summer?

Clara again asks The Question. Three times. Though the second and third times come with some prodding by the Doctor, who affectionately admits, "Do you know I never realized how much I enjoyed hearing that said out loud? Thank you."

During her first upload to The Shard, Clara is "spliced… a computer skills package." Could this be the source of her computer "genius" in "Asylum of the Daleks?," in which "insane hacking skills" applied to another kind of web (i.e. the Pathweb) played—or will play—a vital role.

Incidentally, the agents' base is on Floor 65 of The Shard. And 6 + 5 = 11.

Clara owns a book entitled 101 Places to See. (Another reference to 11?) On the reverse of the first page, which is not printed on, she's written Property of Clara Oswald age… along with her ages 9–24. 16 and 23 are missing from the list. The book also contains an envelope marked DELSA, a red leaf (an implicit fall reference)—which Clara later informs the Doctor is "not a leaf," but "the first page"—and assorted, smaller pieces of paper/other envelopes with writing on them. On the same shelf from which the Doctor pulls 101 Places to See—the shelf beside Clara's bed—are assorted travel/language books (e.g. Latin America, India)—some with titles in foreign languages. Can Clara actually speak these languages? Is that how she is "clever?" Or are the books meant simply to reinforce a connection to travel and exploration—perhaps, not unlink the Doctor's? The front and back covers and "first page" of 101 Places to See feature globes. There is also a globe on the shelf. There was also a really big globe in "The Snowmen."

The pitcher that the Doctor places beside Clara's bed after rescuing her the first time has snowflakes on it. With the Jammie Dodgers, they might be meant to evoke Christmas time—the last time that the Doctor encountered Clara. Somewhat humorously, both the pitcher and the glass that he puts out for Clara are filled with water—not milk (see "Asylum of the Daleks").

In a scene reminiscent of one in "The Snowmen," Clara has a conversation with the Doctor from her window.

Appropriately, when he's not inventing quadricycles, the Doctor rides a Triumph motorcycle. Its license plate is WP62 LWT.