'Doctor Who' is about to ruin emoji for you forever

Doctor Who, like the best horror films, has always been at its strongest when it performs this one weird trick.

The long-running BBC sci-fi show thrives on taking a single, simple, harmless, ordinary thing you see in everyday life (stone statues, showroom dummies), then tweaking it into a creature so terrifying (the Weeping Angels, the Autons) you will never in your life see that object the same way again.

This Saturday, in the new Season 10 episode called "Smile," Doctor Who is about to perform that same trick with that most simple, harmless, ordinary facet of 21st century life: emoji.

If you watch it -- and you should, because it's among the best episodes of new Who -- the smiley face at the end of your texts will take on sinister new meaning.

(No spoilers here, sweetie; my main aim is to alert you that Who has reversed the seasons-long slump that has unfortunately marked the Peter Capaldi era thus far, and is finally going in interesting new directions.)

If you're an old-school Whovian like me, you probably rolled your eyes at that point in the Season 10 trailer when new companion Bill Potts (Pearl Mackie) encounters a robot with a flatscreen face composed of a smiley and a thumbs-up.

"It speaks emoji," says Bill excitedly, and you could almost sense the strain of fiftysomething showrunner Steven Moffat, an unabashed populist, trying to reach his arms out to a millennial audience.

Two things, though. First, "Smile" wasn't written by Moffat, but by Frank Cottrell-Boyce, the screenwriter behind such criminally underrated movies as 24-Hour Party People and Millions.

Cottrell-Boyce tried his hand at a Doctor Who episode once before, in Season 8. It was called In the Forest Of the Night. It was a nice concept (the world is suddenly covered by a large forest that grows overnight; the Doctor has to figure out why).

Unfortunately, like much of the Moffat era, it was marred by a frenetic execution: Too many ideas packed into one story; too many new characters squeezed onto the screen for us to care about any of them.

But that's the second thing: Doctor Who has gone back to basics. And in doing so, the show finds itself newly relevant for 2017 without trying too hard.

If you watched the first episode of Season 10, the charming and cheekily-named "The Pilot," you know that Moffat is swearing off his million-ideas-a-minute freneticism. "The Pilot" was the story of Bill outrunning a monster that has taken the form of her would-be girlfriend with the help of a mysterious professor at her university, simply called The Doctor.

It was a good introduction to the show for any new fans jumping on the bandwagon, even if Moffat was still trying too hard to pack a laugh into every line. (Moffat gonna Moffat, I guess.)

But as a matter of fact, "Smile" is an even better introduction. It's a simple tale reminiscent of classic-era Doctor Who; the Doctor and Bill are the only characters on screen for much of it, and the episode takes its time unfolding the story. Spooky music amps up the creepiness of the empty, sunlit utopia they've entered.

When the emojibots turn evil with skull-filled faces -- again, no spoilers, it's right there in the trailer -- the shiver-worthy moment has been thoroughly earned.

Bill is now at the stage of asking the Doctor all the questions a brand new companion should, and her beginner's mind manages to elicit answers about the Doctor's mysterious past that even long-time fans haven't heard before.

Stick around for the moment where Bill realizes why the Doctor really hasn't fixed the TARDIS -- why this most powerful of time machines has been stuck cloaking itself as a 1960s British police box for the last 54 years. It's as neat a summary of the show as you'll ever get.

The emoji thing isn't just used for robots, by the way. The implications of a future society that communicates mostly through emoji are explored in fascinating ways.

Warning: If you want to get to sleep after watching it, you'll have to be prepared to mould your face into a permanent :).