A three-part comic anthology by Gene Luen Yang and Derek Kirk Kim, each of the three stories in The Eternal Smile deals with crossing the line between fantasy and reality.
In "Duncan's Kingdom", a young knight named Duncan tries to get revenge for the death of his king and win a princess's hand by slaying the evil Frog King. But Duncan is troubled by recurring dreams about a crying woman, and further troubled by a bizarre artifact found in the Frog King's lair: an empty soda bottle.
"Gran'pa Greenbax and the Eternal Smile" is framed around the latest get-rich-quick scheme of cartoon amphibian Gran'pa Greenbax: inspired by a mysterious disembodied smile floating in the sky above a nearby desert, he sets up an evangelical "Church of the Eternal Smile" and tries to make a mint off donations. But his scheme falls apart with less-than-hilarious consequences, and Greenbax makes some unpleasant discoveries about his place in the world...
The third and final story, "Urgent Request", features a put-upon office worker named Janet falling for the infamous "Nigerian royalty" scam. But things take a turn for the weird when her correspondence with "Prince Henry" gives her a surprising boost of confidence... and it only gets weirder when she tracks down and confronts the scammer and demands... a date?
The Eternal Smile contains examples of the following tropes:
- Amusing Injuries: Deconstructed in "Gran'pa Greenbax", Greenbax is horrified when he ends up killing his long-suffering sidekick Filbert during a session of inflicting Amusing Injuries on him.
- Butt-Monkey: Filbert in "Gran'pa Greenbax" (it seems that Norbert, his "real life" inspiration, serves exactly the same purpose).
- The Cameo: Duncan is visible in a crowd briefly at the end of "Gran'pa Greenbax," with his mother. Also, Hiro Nakamura puts in a surprise appearance too!
- Captain Ersatz: Gran'pa Greenbax is so obviously Scrooge McDuck it's painful, with Polly and Molly serving as the Huey, Dewey, & Louie expies and Filbert a combination of Donald Duck (constantly the focus of Gran'pa's bad temper) and Gyro Gearloose (the temperament, the build, the inventions). Gran'pa Greenbax ends up becoming a Deconstruction of Uncle Scrooge. His Quest is outright tragic; he says that he's searched high and low for meaning in his life, and the only thing he's ever found that even comes close to meaning is money — specifically, gold coins, specifically, enough gold coins that he can leap into a lake of them and never hit bottom. At the end, it's uncovered that this is really his yearning to return home — to a real lake, that shines like gold in the sunset, and is deep enough for a normal frog to live very happily. And that's where he returns.
- Cheshire Cat Grin: The titular Eternal Smile.
- Creepy Twins: Gran'pa Greenbax's granddaughters become this when they get a little too into the Church of the Eternal Smile.
- Hair of Gold, Heart of Gold: It would seem that the princess in "Duncan's Kingdom" is sweet and adoring in addition to beautiful — even if she does laugh at Duncan's terrible poetry.
- Happy Place: Forms the central theme of these three otherwise-unrelated stories: how much, if at all, should we let fantasy substitute reality? Duncan (who has some choice in maintaining if not actually creating his fantasy-world) and Gran'pa Greenbax ( who didn't) ultimately choose reality, whereas Janet takes more of a middle-of-the-road solution, using her fantasy to give her courage in reality.
- Lightning Can Do Anything: As Duncan finds, it makes a terrific sword!
- Mind Screw: Most prominently in the first two stories, where nothing is ever as it seems.
- Ominous Latin Chanting: Molly and Polly begin doing this once they start becoming obsessed with the Eternal Smile.
- Personality Chip: Provides the sentience of Gran'pa Greenbax and the other people in his world.
- Regal Ruff: In the story "Duncan's Kingdom", the normally free-spirited princess wears one when she mourns at her father's funeral.
- Single-Minded Twins: Polly and Molly. They're basically only distinguishable by the fact that one wears red, and the other yellow.
- Sliding Scale of Realistic Versus Fantastic: The Gran'pa Greenbax story is farthest on the "fantastic" end (even after the Funny Animal trappings are revealed to be something Darker and Edgier), while "Duncan's Kingdom" and "Urgent Request" are on the realistic end (the latter especially).
- Twist Ending: One apiece, mostly relating to the world in which the reader finds themselves. Duncan is in a coma, and hallucinating a fantasy world where his life's failures are easily conquered. Gran'pa Greenbax is a humble pond-hopper that was modified into the star of a wildly popular TV show. And Janet is on to the Nigerian "prince's" scam from the first.