"Were you really a pilot in a war, Grandpa?" The twins snuggled up to the old man on the couch. Archie was in town, and the children's mother and father were taking advantage of the free babysitting to have an actual date night, movie and all. The parents were glad for the break, but only imperfectly so, since Archie was liable to fill Liselle's and Denny's heads with the most ridiculous stories."Oh, yes indeed," replied Archie, pulling the blanket more closely around the shoulders of the twins. "I flew planes for the French. This was known as the Great War, but I suppose you kids call it World War One nowadays.Denny screwed his head around and regarded his grandfather suspiciously. "World War One ended in 1918," he said. "We just learned that in school. So that would make you…""…older than you suspect!" chuckled Archie. "Oh, it's just good genetics, kiddo. I get it from my great-grandmother's side. She's immortal, you know."Liselle rolled her eyes. "Mom says you tell all kinds of lies," she said. "She says we shouldn't believe a word you say.""Well." Disgruntled, Archie adjusted his glasses and brushed imaginary lint off his sweater. "If you don't want to hear my lies, you probably shouldn't be asking me about the things I have to say.""No, come on, Grandpa," pleaded Denny."We're sorry, we didn't mean to upset you," added Liselle. "Tell us about flying planes.""I've flown all sorts of them," Archie said, somewhat mollified. "There were the Boomerangs I flew in night missions during the Secret War, for instance.""I've never heard of the Secret War," said Denny."Exactly!" hissed Archie, touching the side of his nose."Maybe you should tell us about the planes during World War One," suggested Liselle."Oh, all right," replied Archie. "I flew a Spad. It was one of the first really good combat aircraft – sturdy, dependable and good maneuverability. It was a biplane.""What's a biplane?" asked Denny."It was called a biplane because it had two wings – one on top, one on the bottom. That was how they built planes in those days.""Really?" asked Liselle, eyes slitted with suspicion."Oh, yes; really," replied Archie, all innocence."Did you shoot down any planes?" asked Denny. "With a machine gun?""Most definitely," answered Archie. "For instance there was the one time I shot down that most famous German flying ace, the Red Baron.""Really?!" repeated Liselle unbelievingly."Oh, yes; really," replied Archie, still innocently."I'd like to zoom around in a biplane," said Denny. He made a sound like a zooming plane."The Red Baron zoomed around in a triplane," said Archie. "It was called a Fokker, and it had three wings one over another; one, two, three. The added wing gave it better stability and more endurance in the air.""I don't know about these biplanes and triplanes," said Liselle."Oh, that was nothing," boasted Archie. "People kept on adding more and more wings. The Armstrong-Whitworth FK-10 had four wings. Didn't work right; nobody liked it. But they kept on trying to play around with the number of wings on planes.""I don't believe there was a plane with four wings," said Denny obstinately."The Russians," Archie said stoutly, "designed one with twelve. It looked ridiculous. Didn't fly, of course, but that was the Russians for you.""Why did they build a plane that couldn't fly?" demanded Liselle."Because as it turns out," Archie answered, "it swam beautifully. Skimmed about just below the waves like a flying fish.""I can't imagine a plane with twelve wings," said Denny."It was an awful lot of wings," Archie admitted. "Now the Belgians did their best to split the difference. They designed a triplane with a little fractional wing on the top, just to give it a little boost during takeoff.""It was a three-and-a-half wing plane?" said Liselle incredulously."Actually, they called it a pi-plane," said Archie. Liselle and Denny turned to study his face, but there was no trace of a smile. Their grandfather nodded solemnly."Oh yes," Archie continued. "'L'oeufs', they called them. Beautiful aircraft, very well-rounded. Absolutely terrorized the Huns. Germans came to regard those Belgian planes as synonymous with the Allied air threat. Renamed their own air forces the 'Luftwaffe' in response."Denny and Liselle just looked at one another. There was simply no telling where the tales started and ended."Of course, it was the American entry into the war in the skies that ended the whole thing, don't you know," Archie confided. "Good old American ingenuity.""How many wings did the American planes have?" asked Liselle, but not necessarily because she wanted to hear the answer."That's the very interesting part," said Archie intently. "The Americans realized that in order to beat the Germans in the skies, they would have to reinvent how planes worked. To successfully penetrate German air defenses they would have to fly outside real space."Denny and Liselle stared blankly. "Huh?" said Denny."The Americans," announced Archie, "invented the i-plane. One set of wings provided lift in real space, but another set provided lift in a dimension orthogonal to normal reality! American pilots were able to lift off into imaginary space, circumvent the ack-acks, and strike deep into the Ruhr Valley! And that’s how victory was achieved on the Western front."Liselle shook her head. "Grandpa," complained Denny, "you're just telling stories again.""Bah, what do kids know these days anyways," grumbled Archie, his face fallen. "Can't tell them nothing about what happened in the old days.""That's not true," protested Liselle."Yeah, we really like real history stuff," added Denny. "Just not the fake stories.""You mean like the U-boats?" asked Archie. "Do you know about them?""Yeah, the submarines!" Now Denny was in familiar territory. "They were called 'unterseeboats'.""Yes they were," said Archie. "Wolves of the sea. Nobody could stop the U-boats.""Yeah," said Liselle."Until," appended Archie, "we invented the UU-boats."Denny and Liselle stared."The unter-unterseeboats," amplied Archie. "See, the only way to get at something that could go below the waves was to surprise them with something that went below the ocean floor itself…"Denny and Liselle listened, spellbound.